Astronomy

V471 Tauri's circumbinary brown dwarf non-observation; Applegate, or over-restrictive assumptions?

V471 Tauri's circumbinary brown dwarf non-observation; Applegate, or over-restrictive assumptions?


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tl;dr Has the brown dwarf observation been disproven?

I have just started reading about the interesting object V471 Tauri. The first two sentences of the introduction to The V471 Tauri System: A Multi-datatype Probe Vaccaro et al. (2015):

V471 Tau, a white dwarf-red dwarf eclipsing binary (EB) in the Hyades with orbit period $0^d.52118$, is primarily known for its unique historical role as a stimulus to common envelope evolution theory (Chau et al. 1974; Refsdal 1974; Sparks & Stecher 1974; Ostriker 1976; Paczynski 1976; Alexander et al. 1976; Taam et al. 1978). Other properties include a likely brown dwarf companion to the EB, measured white dwarf spin, mass loss and exchange in a detached binary, differential rotation measured via magnetic spots, spot distributions, accurate white dwarf parameters, and photometric-spectroscopic distance measures that help to pin down the binary's location within the Hyades.

It's the "likely brown dwarf companion" I'd like to ask about. The paper with the catchy title "The First Science Results from SPHERE: Disproving the Predicted Brown Dwarf around V471 Tau" Hardy et al. (2015) SPHERE is a new, advanced adaptive optics system at the Very Large Telescope (VLT). The image below (figure 3) is part of the argument, and the suggestion is that if there is no brown dwarf seen in the band between the two white circles, then the predicted brown dwarf does not exist.

This would be interesting, because an alternative explanation for the slow, periodic drift in the eclipse timing would have to be found. One possibility is the Applegate Mechanism which I don't understand, but may ask a separate question after this.

Back to Vaccaro 2015, section 9, titled "On the Reality of the Third Star" is over six pages of discussion of the underlying assumptions, and if I understand it correctly provides several possible ways in which a suitable brown dwarf could exist but not show up in the SPHERE image. In essence disproving the existence disproof.

I would like to know: Is my understanding of the current situation correct? Have there been more recent developments?

above: Left panel of Fig. 3 of Hardy et al. 2015: "Figure 3. H-band image of V471 Tau obtained on the SPHERE IRDIS instrument at the VLT. Left panel: Resulting image after angular differential imaging (ADI). The area in-between the white circles denotes the 5 sigma predicted position of the brown dwarf… "

above: The monster currently known as SPHERE from here.


For all of these direct imaging results, the critical parameter is the contrast as a function of separation. This lets you know how much fainter an object you can see around the much brighter primary object whose light has been suppressed by the coronograph (the black circle in the center of the star).

From the change in eclipse timings (Figure 1 in their paper) you can predict the expected mass and separation of the third object (proposed brown dwarf) using their equation 1 since you know the mass of the binary. From evolutionary models of brown dwarfs, you can make predictions of how bright the proposed brown dwarf should be for its predicted mass.

You can then look for an object at the right separation in the SPHERE images. This is shown in their Figure 3 (right hand figure of the 2) where they show how bright an object they could see as a function of separation from the primary star; everything above the solid curve is something they should see. The vertical dotted lines show the boundary on the separation of the brown dwarf, predicted from the eclipse timings. The diamond symbol is the predicted brightness of the brown dwarf from the evolutionary models given its mass.

Since this is well above the contrast curve (by a factor of about 15x) and nothing is seen in the images at that separation, this strongly suggests that the proposed brown dwarf does not exist. The only "get-outs" are if the SPHERE team have measured their contrast curve incorrectly (unlikely at the level needed) or our models of how bright brown dwarfs should be are also wrong by about a factor of 15x and the brown dwarf is much, much fainter than predicted.

The Applegate mechanism is a bit weird. The idea is that as the star goes through magnetic activity cycles (as the Sun and a lot of other stars do) and the magnetic field strength grows and shrinks, this causes the shape of the star to change, bulging more or less at the star's equator as the cycle progresses. This changes the amount of angular momentum in the star, which has to couple into the binary orbit as the angular momentum has to be conserved, causing the binary orbit to shrink or expand. This would then explain the change in timings of the eclipses without the need for the third body brown dwarf tugging on binary. Unfortunately the Applegate mechanism, although it may work in V471 Tau, can't explain the variations in a bunch of other binary systems (magnetic field strength not strong enough) so it can't be the only solution for eclipse time variations.

The latest paper I could find that references the Vaccaero et al. 2015 paper, is Vanderbosch et al. 2017. They argue that because of the timing of the eclipses change but the spin period of the white dwarf secondary doesn't change, a third body such as a brown dwarf can't explain the changes as it should change the timing of both "clocks".


The Dragon's Gaze

The gap formation induced by a giant planet is important in the evolution of the planet and the protoplanetary disc. We examine the gap formation by a planet with a new formulation of one-dimensional viscous discs which takes into account the deviation from Keplerian disc rotation due to the steep gradient of the surface density. This formulation enables us to naturally include the Rayleigh stable condition for the disc rotation. It is found that the derivation from Keplerian disc rotation promotes the radial angular momentum transfer and makes the gap shallower than in the Keplerian case. For deep gaps, this shallowing effect becomes significant due to the Rayleigh condition. In our model, we also take into account the propagation of the density waves excited by the planet, which widens the range of the angular momentum deposition to the disc. The effect of the wave propagation makes the gap wider and shallower than the case with instantaneous wave damping. With these shallowing effects, our one-dimensional gap model is consistent with the recent hydrodynamic simulations.

The Gaia Mission, Binary Stars and Exoplanets

On the 19th of December 2013, the Gaia spacecraft was successfully launched by a Soyuz rocket from French Guiana and started its amazing journey to map and characterise one billion celestial objects with its one billion pixel camera. In this presentation, we briefly review the general aims of the mission and describe what has happened since launch, including the Ecliptic Pole scanning mode. We also focus especially on binary stars, starting with some basic observational aspects, and then turning to the remarkable harvest that Gaia is expected to yield for these objects.

Resonances in Retrograde Circumbinary Disks

We analyse the interaction of an eccentric binary with a circular coplanar circumbinary disc that rotates in a retrograde sense with respect to the binary. In the circular binary case, no Lindblad resonances lie within the disc and no Lindblad resonant torques are produced, as was previously known. By analytic means, we show that when the binary orbit is eccentric, there exist components of the gravitational potential of the binary which rotate in a retrograde sense to the binary orbit and so rotate progradely with respect to this disc, allowing a resonant interaction to occur between the binary and the disc. The resulting resonant torques distinctly alter the disc response from the circular binary case. We describe results of three-dimensional hydrodynamic simulations to explore this effect and categorise the response of the disc in terms of modes whose strengths vary as a function of binary mass ratio and eccentricity. These mode strengths are weak compared to the largest mode strengths expected in the prograde case where the binary and disc rotate in the same sense. However, for sufficiently high binary eccentricity, resonant torques open a gap in a retrograde circumbinary disc, while permitting gas inflow on to the binary via gas streams. The inflow results in a time varying accretion rate on to the binary that is modulated over the binary orbital period, as was previously found to occur in the prograde case.


Thursday, July 30, 2015

Hot Jupiter HD 189733b's Transit Detected by SOPHIA

Here we report on the first successful exoplanet transit observation with the Stratospheric Observatory for Infrared Astronomy (SOFIA). We observed a single transit of the hot Jupiter HD 189733 b, obtaining two simultaneous primary transit lightcurves in the B and z' bands as a demonstration of SOFIA's capability to perform absolute transit photometry. We present a detailed description of our data reduction, in particular the correlation of photometric systematics with various in-flight parameters unique to the airborne observing environment. The derived transit depths at B and z' wavelengths confirm a previously reported slope in the optical transmission spectrum of HD 189733 b. Our results give new insights to the current discussion about the source of this Rayleigh scattering in the upper atmosphere and the question of fixed limb darkening coefficients in fitting routines.

PTFO 8-8695: A 3 MYr Old T-Tauri Star Hosting a Potential hot Jupiter

We present Spitzer 4.5micron light curve observations, Keck NIRSPEC radial velocity observations, and LCOGT optical light curve observations of PTFO

8-8695, which may host a Jupiter-sized planet in a very short orbital period (0.45 days). Previous work by citet and citet predicts that the stellar rotation axis and the planetary orbital plane should precess with a period of 300� days. As a consequence, the observed transits should change shape and depth, disappear, and reappear with the precession. Our observations indicate the long-term presence of the transit events (>3 years), and that the transits indeed do change depth, disappear and reappear. The Spitzer observations and the NIRSPEC radial velocity observations (with contemporaneous LCOGT optical light curve data) are consistent with the predicted transit times and depths for the M⋆=0.34 M ⊙ precession model and demonstrate the disappearance of the transits. An LCOGT optical light curve shows that the transits do reappear approximately 1 year later. The observed transits occur at the times predicted by a straight-forward propagation of the transit ephemeris. The precession model correctly predicts the depth and time of the Spitzer transit and the lack of a transit at the time of the NIRSPEC radial velocity observations. However, the precession model predicts the return of the transits approximately 1 month later than observed by LCOGT. Overall, the data are suggestive that the planetary interpretation of the observed transit events may indeed be correct, but the precession model and data are currently insufficient to confirm firmly the planetary status of PTFO

Compact Exoplanets Made With Dark Matter

We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron star matter and white dwarf material. We consider non-self annihilating dark matter with an equation-of-state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from few Km to few hundred Km for weakly interacting dark matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be formed primordially and accrete white dwarf material subsequently. They could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 M ⊙ pulsars set limits on the amount of dark matter inside neutron stars which is, at most, 10𕒺M ⊙ .


Spectroscopic radial velocity

Light from an object with a substantial relative radial velocity at emission will be subject to the Doppler effect, so the frequency of the light decreases for objects that were receding (redshift) and increases for objects that were approaching (blueshift).

The radial velocity of a star or other luminous distant objects can be measured accurately by taking a high-resolution spectrum and comparing the measured wavelengths of known spectral lines to wavelengths from laboratory measurements. A positive radial velocity indicates the distance between the objects is or was increasing a negative radial velocity indicates the distance between the source and observer is or was decreasing.

William Huggins ventured in 1868 to estimate the radial velocity of Sirius with respect to the Sun, based on observed red shift of the star's light. [5]

Diagram showing how an exoplanet's orbit changes the position and velocity of a star as they orbit a common center of mass.

In many binary stars, the orbital motion usually causes radial velocity variations of several kilometers per second (km/s). As the spectra of these stars vary due to the Doppler effect, they are called spectroscopic binaries. Radial velocity can be used to estimate the ratio of the masses of the stars, and some orbital elements, such as eccentricity and semimajor axis. The same method has also been used to detect planets around stars, in the way that the movement's measurement determines the planet's orbital period, while the resulting radial-velocity amplitude allows the calculation of the lower bound on a planet's mass using the binary mass function. Radial velocity methods alone may only reveal a lower bound, since a large planet orbiting at a very high angle to the line of sight will perturb its star radially as much as a much smaller planet with an orbital plane on the line of sight. It has been suggested that planets with high eccentricities calculated by this method may in fact be two-planet systems of circular or near-circular resonant orbit. [6] [7]


2. Nomenclature

400 pc) [103,104,105,106,107,108] and galactic latitude, have solar metallicity [109,110], are located in the same direction towards the antapex in the Ori OB1 association, and project the same angular size on the sky of about 1 deg. ONC in the Orion Sword is slightly younger (t

1 Ma) than σ Orionis in the Orion Belt (t

3 Ma) [34,111,112,113,114]. As a result, the extinction is larger in ONC than in σ Orionis: while one could see all Milky Way stars in the line of sight of the Orion Belt with an ultradeep survey [115], there is only contamination by foreground sources towards the Orion Sword. The age and extinction effects compensate each other, and the substellar boundary in ONC and σ Orionis roughly lies at the same magnitude I =17−18 mag [35].


Systems of 2019 [ edit | edit source ]

    (Nov 19) - The brightest and possibly nearest star (1600 ly) around which a planet was discovered using microlensing detected planet (microlense event TCP J05074264+2447555 in Taurus). Unlike most such planets, this is in a direction away from the galactic center and is nearby, and thus one of the few to have been confirmed using other techniques, and was followed up with radial velocity measurements taken from a network of telescopes around the world. Accidentally discovered while monitoring the sky for star brightenings that could indicate a nova. Planet Lb was found to be in an Earthlike orbit (1.1 AU) and a little more massive than Neptune (20 ME). Since the star is less massive than the sun (0.6 MS), the planet is at the edge of the snow line. It orbits closer in than most microlense detected planets and shows that Neptune sized planets at the frost line may be common. This is an important case study because it is thought that the most effective place to form Neptune sized planets is at the frost line. It is ideally situated for direct observation by future telescopes. (Oct 19) - Copernicus is also known as Rho Cancri, 55 Cancri, Rho1 Cancri, HR 3522, Gl 324, and HD 75732. Wide binary star consisting of a sun-like primary (A, though super metal rich) and a red-dwarf secondary (B) separated by 1,100 AU, 41 light years away. Star A contains five exoplanets, the first system found with four or five planets. It has three tightly packed eccentric planets close in to the star, including planet Jannsen (e, hot Super Earth/Neptunian), Galileo (b, warm Jupiter), and Brahe (c, hot Saturn), followed by an eccentric Saturn in the habitable zone (Harriot, f) and a Jupiter analog, Lippershey (d). Planet e was heralded as the first Neptunian discovered. It was later found to be the shortest-period planet discovered (18 hours) and to transit. Its density was measured and determined to be rocky, and thus re-dubbed the first Super-Earth discovered. It was then the first super-Earth to have its light detected (by Spitzer in the infrared). The planet has about half of Neptune's mass, but is Earth-like in size and density (2.17 Earth Radius). Studies taking into account the composition of the star suggested that it was largely made of diamond, with graphite at the surface (the first diamond planet around a Sunlike star), and the first terrestrial found with fundamentally different surface composition and processes than Earth. This was later refuted when it turned out there wasn't as much carbon in the parent star as believed. Earlier studies that assumed an Earth-like composition suggested that it would be covered with an ocean of super-critical water. The brightness of the planet was found to have raised dramatically, possibly the aftermath of cloud cover due to a volcanic eruption. The brightness of the star (also closest known to transit and only known naked eye star to do so) makes it more easily studied than other hot super Earths. It was found to be dark and its sun-facing side hot enough to melt metal. It became the first super Earth to have its atmospheric composition measured (mostly hydrogen and helium with hints of hydrogen cyanide which would only dominate in a carbon-rich environment and no traces of water vapor) and temperature mapped, and the large hemispherical temperature differences suggest little atmosphere to transport heat. Planet b (one of the original 4 Hot Jupiters discovered) is the first "warm Jupiter" found to have a puffed up atmosphere and it probably at the outer limit from the star at which a planet can lose its atmosphere in this way. Its outer atmosphere skims the surface of the star, which was detected when attempting to detect an atmosphere around transiting Janssen. The strong interaction between planets Galileo and Brahe can be detected in measurements, and it took a while to find a fit that would allow them to survive over long periods of time. Harriot is a very eccentric Saturnian in the habitable zone. Planet d is a super jovian at Jupiter-like distances, which was the first found at true Jupiter distances and still the exoplanet discovered with dopplar spectrometry with the largest known semi-major axis. It was first thought to be circular, then eccentric, and then circular again. The distant outer star causes Lippershey's axis to flip on its axis every million years. Lippershey in turn causes the other planets to flip, including its star. The axis tilt of transiting planet e should be determined at some point. "Bode's law" predicts four undiscovered planets. One of the first 20 exoplanet systems allowed to be given common names by the IAU. (Oct 19) - The shortest period transiting Hot Jupiter known when discovered in 2008 and the first carbon-rich planet ever found (more Carbon than Oxygen). One of the two largest known planets at 1.79 Jupiter radii. Hottest known exoplanet at time of its discovery. Planet is being ripped apart by star. It is stretched in the shape of a rugby ball and leaves a ring around its star. Huge cloud of material detected around the planet containing elements never before detected on an exoplanet. This cloud is much larger than expected, and shrouds the entire star, making it undetectable at some wavelengths. Studying this cloud could reveal magnetic properties of the stellar system. Magnesium found in this shroud supports the blow-off theory where Hydrogen escapes from the planet so quickly other material is blown off with it. Two other Hot Jupiters are known to have planetary enveloping clouds, and others as close are expected to have similar system wide clouds, but not those further away. It has much more methane than water vapor. It may produce shock waves as it plows through its star's stellar wind (the first evidence of shocks around an exoplanet, like Earth and Saturn's bowshocks), possibly produced by a strong planetary magnetic field. This could protect its atmosphere from being stripped away. It could have a diamond core and other terrestrial planets in system would have black spots on them and also be carbon based. One of 5 exoplanets whose water abundance was measured by Hubble in 2013 and found to be less abundant than expected, probably due to a layer of haze or dust blocking detection.. (Oct 19) - Lich (PSR B1257+12) is a millisecond pulsar 1000 ly away in Virgo around which the first confirmed exoplanets were detected. Has an innermost 2 Moon-sized planet Draugr (A or b, 0.19 AU, the least massive known exoplanet), a 4.3 ME planet Poltergeist (B or c) at 0.36 AU, and a 3.9 ME planet Phobetor (C or d) at 0.46 AU. Variations in the pulsar's 6.22 ms period led to the planets' discovery. Draugr and Poltergeist are near enough to each other to perturb each others orbits, and this was detected and used to prove they existed. The planets were designated with capitol letters before naming conventions were established, and A was discovered last and thus dubbed because it was closer. An outer Saturn sized planet was disproved, as was its successor Dwarf Planet hypothesis. The system may have an asteroid or comet belt. The planets may be second generation. So far, only one other pulsar has been found to have a planet. One of the first 20 exoplanet systems allowed to be given common names by the IAU. The theme of the naming of this system is "undead" creatures, since a pulsar is an "undead" star. The star Lich is named after an undead creature that controls other undead creatures, Draugr is a Norse undead creature, Poltergeist is a "noisy ghost" in German, and Phobetor is a Greek deity of nightmares. (Oct 19) - YZ Ceti is also called L 275-22 and Gl 54.1. It is a nearby Red Dwarf flare star that's only 1.6 ly from Tau Ceti. (Oct 19) - Contains TrES-2, which was the most massive nearby transiting planet until the discovery of Hat-P-2 b. It has a large radius for a planet not considered inflated. A large ground-based telescope method of observation was pioneered on this planet. Since its in Keplar's field of view, it was observed by it as a test subject and dubbed Kepler1b. A second planet is possibly responsible for fluctuations in the first's inclination. Kepler determined that it is the darkest known planet, blacker than coal, due to its extremely low dimming and brightening detected during transits. It would appear black except for some faint red tinge. This conflicts with current theories, which thought that a Hot Jupiter could only get as dark as Mercury. It appears that the planet is too hot for reflective clouds to form and instead its atmosphere contains light-absorbing chemicals. An off-the-cuff nickname Erebus (Greek god of darkness) has been suggested. It was also the first planet whose phases have been detected. (Oct 19) - Star system 120 ly away in Cygnus with the second discovered transiting Super-Neptune and the least massive transiting planet known at the time. Also observed by Kepler and dubbed "Kepler 3b". Orbit unusually eccentric for a Hot Neptune (5 day period) and is inclined 103deg to its orange dwarf star's rotation. Natural radio waves may have been detected coming from the planet. Radial drifts may point to another planet. It was the first smaller planet found to have clear skies (the four previous planets studied were cloudy), which allowed its atmospheric composition to be studied, which was composed primarily of hydrogen and helium with some water (which would be over 1000F). (Oct 19) - A very old nearby ultra-cool dwarf star (not much larger than Jupiter) 39.13 ly away with seven transiting Earth-sized planets, more than any other system, and the first such planets around such a star. First planets found by the TRAnsiting Planets and PlanetesImals Small Telescope. The planets are very compact and the gravitational interactions are significant, with resonances linking all of them, making it possible to study their mass and densities. They're named in order of distance to star. When the innermost planet b completes 8 orbits, the next planets complete 5, 3, and 2 respectively. The outermost planet (h) was predicted to have a period in a certain resonance with the other outer planets, and this was confirmed. When h orbits twice, g orbits 3 times and f 4 times. Hubble confirmed that non of the HZ planets have extended Hydrogen atmospheres. At first, the innermost two are potentially habitable and represent the easiest to study planets for biosignatures to be detected, and the third was thought to be outside the habitable zone. The first two planets (b, c) are somewhat larger than the earth at the inner edge of the habitable zones (receive the amount of energy half-way between Mercury and Venus and Venus) and orbit at 1.5 and 2.4 days. The atmospheres of the inner planets are thought to have been destroyed by the stars intense solar wind withing millions of years. Planet b and c likely have molten rock mantles due to tidal stresses, while c likely has a rocky surface with Io-like tidally induced volcanoes and a largely rocky interior. The further out planets' atmospheres could have survived for billions of years though. The next two planets (d, e) are somewhat smaller than Earth and are a little more and a little less radiated than it in the middle of the HZ. Planet d (the smallest) likely has a global ocean, while e most likely has a largely rocky interior. Studies have shown that, depending on the composition and strength of the planet's own magnetic field, the star's magnetic field could cause induction heating to occur significantly in the middle planets. This could turn the surface into magma, or at least increase volcanic activity, raising the chances of a greenhouse. The next two planets (f, g) are somewhat larger than Earth and orbit in the outer habitable zone (at Mars like distances and at the outer edge). Planet f was at first thought to be the most habitable, but now next planet out g appears to be the most habitable. The view from the fifth planet would be remarkable, with the star appearing 10 times larger than the sun does in our sky, and the other planets appearing twice the size of the moon. Planet h is the only known planet outside the habitable zone and receives about the same irradiation as Ceres does, and yet still orbits six times closer than mercury does from the sun. There was a race among astronomers using kepler data to determine h's orbit. A study on potential cometary impacts found that the outer 3 planets could have had their original atmosphere's obliterated by the impacts, but that this would also supply new volatiles for a new atmosphere, including enough water for one earth ocean mass, suggesting they would have more massive atmospheres than the other planets. (Oct 19) - Alpha Centauri is also known as Rigil Kentaurus. A is also known as HD 128620 and HR 5459, B is HD 128621 and HR 5460, and C is Proxima Centauri. It is the nearest star system to the Sun. Contains a yellow dwarf star a little bigger than the Sun and an orange star a little smaller orbiting each other orbiting each other about the distance Uranus is from the Sun (varies from Saturn like to Neptune like), as well as a distant Red Dwarf companion Proxima that may or may not be orbiting the other two.

    Stellar fingerprinting suggests a high probability that a planet orbits star A, due to dearth of Iron around star. Russian astronomers announced the detection of a second planet orbiting the binary pair at 80 AU with a 100 year period, which appears to be false. The stars in the system will become markedly closer together in 2016, making observations much more difficult and one follow up failed to find it. The system is the first target for the European Cheops exoplanet space telescope.

    A planet was thought to have been discovered around star B and detected by HARPS. It would have been an Earth-massed rocky-iron planet with no atmosphere at epistellar distances around the orange dwarf star B. This would have been the least massive planet found around a sunlike star. The planet was informally and controversially named by Uwingu during a fund raising naming contest Albertus Alauda, after a participant's grandfather. Earthlike planets are not detectable in the habitable zone with present radial velocity methods. Technique for detection of planet is a source of doubt for some and it has yet to be independently verified. A team thought they might have detected a transit of this planet, but further observations showed the timing wasn't consistent. It is possible that a second further out (20.4 day period) Earth-sized planet is altering the transit times of the first. A cheap crowdfunded satellite devoted to studying this star could confirm the planets. The star was observed to be a good candidate to host a "super Habitable" planet, which would have 25% more gravity than the Earth, shallow seas, flatter landscape, higher atmospheric pressure, and the 6 BYO star would be stable for life longer.

    Proxima, a small flare star, was discovered in 1915 by Robert Ines, who named it. Long suspected planet around Proxima found not to exist. The Pale Red Dot project is dedicated to finding a planet around Proxima using dopplar spectrometry. As Proxima passes in front of two stars (once in 2014, again in 2016), any planets within 5 AU should be detectable via microlensing using the HST. It is known that no planets of Neptune sized mass exist within 1 AU and no Jovians with periods up to 1000 days, or transiting planets exist. An Earth-like planet in the habitable zone was discovered around Proxima Centauri. In 2017, a large stellar flare erupted and bombarded the planet, making it likely that the atmosphere has been completely stripped away by events such as this and not a good candidate for life. It was thought that a lot of dust existed in the system, making it feasable that the star had a rich complement of planets, but this seems to not be the case.


Wednesday, November 25, 2015

KIC 8462852: Its "Only" Comets, not Megastructures. Move Along, Alien Hunters

Was it a catastrophic collision in the star's asteroid belt? A giant impact that disrupted a nearby planet? A dusty cloud of rock and debris? A family of comets breaking apart? Or was it alien megastructures built to harvest the star's energy?

Just what caused the mysterious dimming of star KIC 8462852?

Massimo Marengo, an Iowa State University associate professor of physics and astronomy, wondered when he saw all the buzz about the mysterious star found by citizen scientists on the Planet Hunters website.

Those citizen scientists were highlighting measurements of star brightness recorded by NASA's Kepler spacecraft. Tiny dips in a star's brightness can indicate a planet is passing in front of the star. That's how Kepler astronomers - and citizen scientists using the internet to help analyze the light curves of stars - are looking for planets.

But this star had deep dips in brightness - up to 22 percent. The star's brightness also changed irregularly, sometimes for days and even months at a time. A search of the 150,000-plus stars in Kepler's database found nothing like this.

So Marengo and two other astronomers decided to take a close look at the star using data taken with the Infrared Array Camera of NASA's Spitzer Space Telescope. They report their findings in a paper recently published online by The Astrophysical Journal Letters.

"The scenario in which the dimming in the KIC 8462852 light curve were caused by the destruction of a family of comets remains the preferred explanation . " wrote the three - Marengo Alan Hulsebus, an Iowa State doctoral student and Sarah Willis, a former Iowa State graduate student now with the Massachusetts Institute of Technology's Lincoln Laboratory.

HD 139614b: a Three Jupiter Mass Orbiting in a Protoplanetary Disk at 4.5 AU

Spatially resolving the inner dust cavity of the transitional disks is a key to understanding the connection between planetary formation and disk dispersal. The disk around the Herbig star HD 139614 is of particular interest since it presents a pretransitional nature with an au-sized gap, in the dust, that was spatially resolved by mid-IR interferometry. Using new NIR interferometric observations, we aim to characterize the 0.1-10

139614 disk further and identify viable mechanisms for the inner disk clearing. We report the first multiwavelength radiative transfer modeling of the interferometric data acquired on HD

139614 with PIONIER, AMBER, and MIDI, complemented by Herschel/PACS photometries. We confirm a gap structure in the um-sized dust, extending from about 2.5 au to 6 au, and constrained the properties of the inner dust component: e.g., a radially increasing surface density profile, and a depletion of 10^3 relative to the outer disk. Since self-shadowing and photoevaporation appears unlikely to be responsible for the au-sized gap of HD

139614, we thus tested if dynamical clearing could be a viable mechanism using hydrodynamical simulations to predict the gaseous disk structure. Indeed, a narrow au-sized gap is expected when a single giant planet interacts with the disk. Assuming that small dust grains are well coupled to the gas, we found that a

Mjup planet located at 4.5 au from the star could, in less than 1 Myr, reproduce most of the aspects of the dust surface density profile, while no significant depletion in gas occurred in the inner disk, in contrast to the dust. However, the dust-depleted inner disk could be explained by the expected dust filtration by the gap and the efficient dust growth/fragmentation in the inner disk regions. Our results support the hypothesis of a giant planet opening a gap and shaping the inner region of the HD

HD 106906 has a Ring-like Disk Observed at 65 AU

106906AB is so far the only young binary system around which a planet has been imaged and a debris disk evidenced thanks to a strong IR excess. As such, it represents a unique opportunity to study the dynamics of young planetary systems. We aim at further investigating the close (tens of au scales) environment of the HD

106906AB system. We used the extreme AO fed, high contrast imager SPHERE recently installed on the VLT to observe HD

106906. Both the IRDIS imager and the Integral Field Spectrometer were used. We discovered a very inclined, ring-like disk at a distance of 65

au from the star. The disk shows a strong brightness asymmetry with respect to its semi-major axis. It shows a smooth outer edge, compatible with ejection of small grains by the stellar radiation pressure. We show furthermore that the planet's projected position is significantly above the disk's PA. Given the determined disk inclination, it is not excluded though that the planet could still orbit within the disk plane if at a large separation (2000--3000 au). We identified several additional point sources in the SPHERE/IRDIS field-of-view, that appear to be background objects. We compare this system with other debris disks sharing similarities, and we briefly discuss the present results in the framework of dynamical evolution.

234 Planetary Candidates Around 208 Host Stars Fromt he First Year of the K2 Mission

The Kepler Space Telescope is currently searching for planets transiting stars along the ecliptic plane as part of its extended K2 mission. We processed the publicly released data from the first year of K2 observations (Campaigns 0, 1, 2, and 3) and searched for periodic eclipse signals consistent with planetary transits. Out of 59,174 targets we searched, we detect 234 planetary candidates around 208 stars. These candidates range in size from gas giants to smaller than the Earth, and range in orbital periods from hours to over a month. We conducted initial reconnaissance spectroscopy of 68 of the brighter candidate host stars, and present high resolution optical spectra for these stars. We make all of our data products, including light curves, spectra, and vetting diagnostics available to users online.


V471 Tauri's circumbinary brown dwarf non-observation Applegate, or over-restrictive assumptions? - Astronomy

J1. "High Resolution Vidicon Spectrophotometry. I. Variable Mass Loss from Arcturus and the Hypothesis of Giant Convective Elements", 1977, Ap.J.211, 453, Chiu, Adams, Basri, Linsky, Maran, Hobbs.

J2. "Stellar Model Chromospheres. VII. Capella (G5III+), Pollux (K0III), and Aldebaran (K5III)", 1978, Ap.J. 220, 962, Kelch, Linsky, Basri, Chiu, Chang, Maran, Furenlid.

J3. "IUE Observations of Cool Stars: alpha Aur, HR 1099, lambda And, and epsilon Eri", Nature 275, 389, 1978, Linsky, Ayres, Basri, Morrison, et al.

J4. "Lyman-alpha Rocket Spectra and Models of the Quiet and Active Solar Chromosphere Based on Partial Redistribution Diagnostics", Ap.J.230, 924, 1979, Basri, Linsky, Bartoe, Brueckner, VanHoosier.

J5. "Outer Atmospheres of Cool Stars. II. Mg II Flux Profiles and Chromospheric Radiative Loss Rates", Ap.J. 234, 1023, 1979, Basri & Linsky.

J6. "Outer Atmospheres of Cool Stars. III. Cool Stellar Winds", 1980, Ap.J.235, 519, Haisch, Linsky, Basri.

J7. "Formation of Chromospheric Resonance Line Profiles in Supergiants" , 1980, Ap.J. 242, 1133, Basri.

J8. "Outer Atmospheres of Cool Stars. VII. High Resolution, Absolute Flux Profiles of the Mg II h and k Lines in Stars of Spectral Type F8 to M5", 1980, Ap.J. Supp. 44, 383, Stencel, Mullan, Linsky, Basri, Worden.

J9. "Outer Atmospheres of Cool Stars. VIII. IUE Observations and Chromospheric Models for the Supergiant Stars beta Draconis, epsilon Geminorum, and alpha Orionis", 1981, Ap.J. 251, 162, Basri, Linsky, Eriksson.

J10."Outer Atmospheres of Cool Stars. XII. High Dispersion IUE Spectra of Five Late-Type Dwarfs and Giants", Ap.J. 256, 550, 1982, Ayres, Linsky, Basri, Landsman, Henry, Moos, Stencel.

J11."The Enigmatic H-alpha Line of FK Comae: Last Stages of a Coalesing Binary"", 1982, Ap.J. 260, 735, Walter & Basri.

J12."The Soft X-ray Spectrum of Sirius B: The Photospheric Hypothesis", 1982, Ap.J. 261, L81, Martin, Basri, Lampton, Kahn.

J13."Extreme Ultraviolet Spectrophotometry of the Hot White Dwarf HZ43: Detection of He II in the Stellar Atmosphere", 1982, Ap.J. 262, 717, Malina, Bowyer, Basri.

J14."Ultraviolet and X-ray Detection of the 56 Peg System (K0IIp+WD): Evidence for Accretion of a Cool Stellar Wind onto a White Dwarf", 1982, Ap.J.263, 269, Schindler, Stencel, Linsky, Basri, Helfand.

J15."First Observations of Extra-solar Coronal Structure: Activity in the AR Lacertae System", 1982, Ap.J. 267, 665, Walter, Gibson, Basri.

J16."The Chromospheric Hypothesis for T Tauri Stars", 1984, Ap.J.277, 725, Calvet, Basri, Kuhi.

J17."An Analysis of Scattered Light in Low Dispersion IUE Spectra", 1984, Astr. & Ap. 144, 161, Basri, Clarke, Haisch.

J18."A Study of GOV-G5V Solar-type Stars with IUE Spectra", 1985, Ap.J. Suppl. 58, 179, Haisch & Basri.

J19."Simultaneous Observations of CaII and MgII Emission in T Tauri Stars", 1985, Ap.J. 293, 575, Calvet, Basri, Imhoff, Giampapa.

J20."Stellar Activity in Synchronized Binaries I. Dependence on Rotation", 1985, Ap.J. 298, 761, Basri, Laurent, Walter.

J21."Stellar Activity in Synchronized Binaries: II. A Correlation Analysis, with Single Stars", 1987, Ap.J. 316, 377, Basri.

J22."The Atmospheres of T Tauri Stars. I. Calibrated High-Resolution Observations of Moderately Active Stars", 1987, Ap. J. 318, 823, Finkenzeller & Basri.

J23."Accretion Disks Around T Tauri Stars", 1988, Ap. J. 330, 350, Bertout, Basri, Bouvier.

J24."Physical Realism and the Analysis of Stellar Magnetic Fields", 1988, Ap.J. 330, 274, Basri & Marcy.

J25."Observations of the Type II Supernova 1986I in M99", 1989, A.J.97, 186, 12th in list of 24 authors, C.R. Pennypacker 1st.

J26."Accretion Disks Around T Tauri Stars. II. Balmer Emission", 1989, Ap.J.341, 340, Basri & Bertout.

J27."Physical Realism and the Analysis of Stellar Magnetic Fields. II. K Dwarfs", 1989, Ap.J. 345, 414, Marcy & Basri.

J28."Photospheric Activity on Main Sequence Stars", 1989, P.A.S.P.101, 528, Basri, Wilcots, Stout.

J29."Physical Realism in the Analysis of Stellar Magnetic Fields. III. Flux Tubes and Multi-component Atmospheres", 1990, Ap. J. 360, 650, Basri, Marcy, Valenti.

J30."Hamilton Echelle Spectra of Young Stars I. Optical Veiling", 1990, Ap.J. 363, 654, Basri & Batalha.

J31."The Young Cluster in NGC 1275: H-alpha Linewidth and Star-Formation Properties", 1990, A.J. 100, 1805, Shields, Fillipenko, Basri.

J32."The Temperature Scale of Hot DA White Dwarfs: Temperatures from Far-Ultraviolet Continuum Fluxes", 1990, Ap.J. 359, 483, Finley, Basri, Bowyer.

J33."The Lithium Resonance Line in T Tauri Stars", 1991, Astr. & Ap. 252, 625, Basri, Martín, Bertout.

J34."Limits on the Magnetic Flux on Pre-main Sequence Stars", 1992, Ap. J. 390, 622, Basri, Marcy, Valenti.

J35."CCD Photometry of T Tauri Stars", 1992, P.A.S.P. 104, 1144, Richter, Basri, Perlmutter, Pennypacker.

J36."The Atmospheres of T Tauri Stars. II. Chromospheric Line Fluxes and Veiling", 1993, Ap.J. 412, 363, Batalha & Basri.

J37."A Synoptic Study of H-alpha Line Profile Variability in the T Tauri Star SU Aurigae", 1993, Ap. J. Suppl. 89, 321, Giampapa, Basri, Johns, Imhoff.

J38."T Tauri Stars in Blue", 1993, A.J. 106 2024, Valenti, Basri, Johns.

J39."A Far Ultraviolet Flare on a Pleiades G Dwarf", 1994, Ap. J.420, L33, Ayres, Stauffer, Simon, Stern, Antiochos, Basri, Bookbinder, Brown, Doschek, Linsky, Ramsey, Walter.

J40."Zeeman Enhancement of Lines in Extremely Active K Dwarfs", 1994, Ap.J.431, 844, Basri & Marcy.

J41."A Search for Lithium in Pleiades Brown Dwarf Candidates Using the Keck HIRES Echelle", 1994, Ap.J. 428, L57, Marcy, Basri, Graham.

J42."Infrared Zeeman Analysis of Epsilon Eridani", 1995, Ap.J.439, 939, Valenti, Marcy, Basri.

J43."A Surprise at the Bottom of the Main Sequence - Rapid rotation and no H-alpha Emission", 1995, A.J. 109, 762, Basri & Marcy.

J44."Hamilton Echelle Spectra of Young Stars II: Time Series Analysis of H-alpha Variations", 1995, A.J. 109, 2800, Johns, Basri.

J45."The Line Profile Variability of SU Aur", 1995, Ap.J. 449, 341, Johns & Basri.

J46."Lithium in Brown Dwarf Candidates: The Mass and Age of the Faintest Pleiades Stars", 1996, Ap.J. 458, 600, Basri, Marcy, Graham.

J47."The Narrow Emission Lines of T Tauri Stars", 1996, Ap.J. Supp.103, 211, Batalha, Stout-Batalha, Basri, Terra.

J48."Night-Sky High-Resolution Spectral Atlas of OH and O 2 Emission Lines for Echelle Spectrogram Wavelength Calibration", 1996, P.A.S.P.108, 277, Osterbrock, Fulbright, Martel, Keane, Trager, Basri.

J49."Dynamic Processes in Be Star Atmospheres. IV. Common Attributes of Line Profile `Dimples" ", 1996, Ap.J. 469, 336, Smith, Plett, Johns, Basri, Thomson, Aufdenberg.

J50."Pressure Broadening in VB10: High Resolution Spectroscopy with Keck", 1996, M.N.R.A.S. 283, 821, Schweitzer, Hauschildt, Allard, Basri.

J51."Brown Dwarfs in the Pleiades Cluster Confirmed by the Lithium Test", 1996, Ap.J. 469, L53, Rebolo, Martín , Basri, Marcy, Zapatero-Osorio.

J52."The Spectral Variability of the T Tauri Star DF Tau", 1997, Ap. J. 474, 433, Johns-Krull & Basri.

J53."Lithium in Very Low-Mass Stars in the Pleiades" 1997, A.J.113, 296, Oppenheimer, Basri, Nakajima, Kulkarni.

J54."Dynamic Processes in Be Star Atmospheres. V. Helium Line Emissions from the Outer Atmosphere of lambda Eridani", 1997, Ap.J.481, 467, Smith, Cohen, Hubeny, Plett, Basri, Johns-Krull, MacFarlane, Hirata.

J55."The Classical T Tauri Spectroscopic Binary DQ Tau.I. Orbital Elements and Light Curves", 1997, A.J. 113, 1841, Mathieu, Stassun, Basri, Jensen, Johns-Krull, Valenti, Hartmann.

J56."Hamilton Echelle Spectroscopy of the 6 March 1993 Solar Flare", 1997, Ap.J.Supp. 112, 221,Johns-Krull, Hawley, Basri, Valenti.

J57."The Classical T Tauri Spectroscopic Binary DQ Tau.II. Emission Line Variations with Orbital Phase", 1997, A.J. 114, 781, Basri, Johns-Krull, Mathieu.

J58."The Temperature Scale and Mass Distribution of Hot DA White Dwarfs", 1997, Ap.J. 488, 375, Finley, Koester, Basri.

J59."Keck HIRES Spectra of the Brown Dwarf DENIS-P J1228.2-1547", 1997, Astr. & Ap. 327, L29, Martín, Basri, Delfosse, Forveille.

J60."New Brown Dwarfs in the Pleiades Cluster", 1997, Ap.J. 491, L81, Zapatero-Osorio, Rebolo, Martín, Basri, Magazzù.

J61."A New Pleiades Member at the Lithium Substellar Boundary", 1998, Ap.J.499, L61, Martín, Basri, Gallegos, Rebolo, Zapatero-Osorio, Bejar.

J62."The First L-type Brown Dwarf in the Pleiades", 1998, Ap.J.507, L41, Martín, Basri, Zapatero-Osorio, Rebolo, García-López

J63."Discovery of a Very Low-Mass Binary with HST/NICMOS", 1998, Ap.J.509, L113, Martín, Basri , Brandner, Bouvier, Zapatero-Osorio, Rebolo, Stauffer, Allard, Baraffe, Hodgkin.

J64."The Mass and Age of Very Low Mass Members of the Open Cluster alpha Persei", 1999, Ap.J. 510, 266, Basri & Martín.

J65."A Search for Companions to Nearby Brown Dwarfs: The Binary DENIS-P J1228.2-1547", 1999, Science 283, 1718, Martín, Brandner, Basri.

J66."The Lithium Test in Young Brown Dwarf Candidates", 1999, A.J.118, 1005, Martín, Delfosse, Basri, Goldman, Forveille, Zapatero-Osorio.

J67."Evidence of a Supernova Origin for the Black-Hole in GRO J1655-40 (Nova Scorpii 1994)", 1999, Nature 401, 142, Israelian, Rebolo, Basri, Casares, Martín.

J68."An L-type Substellar Object in Orion: Reaching the Mass Boundary Between Brown Dwarfs and Giant Planets", 1999, Ap.J. 524, 115, Zapatero-Osorio, Béjar, Rebolo, Martín, Basri.

J69."PPl15: The First Brown Dwarf Spectroscopic Binary", 1999, A.J.118, 2460, Basri & Martín.

J70."Spectroscopic Classification of Late-M and L Field Dwarfs", 1999, A.J.118, 2466, Martín, Basri, Zapatero-Osorio.

J71."Accretion-induced Lithium Line Enhancements in Classical T Tauri Stars: RW Aurigae", 2000, Ap.J. 532, 474, Stout-Batalha, Batalha, Basri.

J72."An Effective Temperature Scale for the Late M and L Dwarfs, from Resonance Absorption Lines of Cs I and Rb I", 2000, Ap.J. 538, 363, Basri, Mohanty, Allard, Hauschildt, Delfosse, Martín, Forveille, Goldman.

J73."Profiles of Strong Permitted Lines in Classical T Tauri Stars", 2000, A.J. 119, 1881, Alencar & Basri.

J74."A Survey for Low-Mass Stars and Brown Dwarfs in the Upper Sco OB Association", 2000, A.J. 120, 479, Ardila, Martín, Basri.

J75."Chandra Detection of an X-Ray Flare from the Brown Dwarf LP 944-20", 2000, Ap.J. 538, L141, Rutledge, Basri, Martín, Bildsten.

J76."Ultraviolet Spectral Variability in the Classical T Tauri Star BP Tau", 2000, Ap.J. 539, 834, Ardila & Basri.

J77."Membership and Muliplicity Among Very Low Mass Stars and Brown Dwarfs in the Pleiades Cluster", 2000, Ap.J. 543, 299, Martín, Brandner, Bouvier, Luhman, Stauffer, Basri, Zapatero-Osorio, Barrado.

J78."Oxygen in the Very Early Galaxy", 2000, Ap.J., 551, 833, Israelian, Rebolo, Garcia-Lopez, Bonifacio, Molaro, Basri, Shchukina.

J79."The Spectral Variability of the Classical T Tauri Star DR Tau'', 2001, A.J., 122, 3335, Alencar, Johns-Krull, Basri.

J80."Observations of T-Tauri Stars Using HST-GHRS: I. Far Ultraviolet Emission Lines'', 2002, Ap.J., 566, 1100, Ardila, Basri, Walter, Valenti, Johns-Krull.

J81."Observations of T-Tauri Stars Using HST-GHRS: II. MgII and Optical Lines'', 2002, Ap.J., 567, 1013, Ardila, Basri, Walter, Valenti, Johns-Krull.

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J88. "Multiplicity of Nearby Free-Floating Ultracool Dwarfs: A Hubble Space Telescope WFPC2 Search for Companions", 2003, A.J., 126, 1526, Bouy, Brandner, Martín, Delfosse, Allard, Basri.

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J91. "X-Ray Properties of Pre-Main-Sequence Stars in the Orion Nebula Cluster with Known Rotation Periods", 2004, A.J., 127, 3537, Stassun, Ardila, Barsony, Basri, Mathieu.

J92. "Measuring Fundamental Parameters of Substellar Objects. I. Surface Gravities", 2004, Ap.J., 609, 854, Mohanty, Basri, Jayawardhana, Allard, Hauschildt, Ardila.

J93. "Measuring Fundamental Parameters of Substellar Objects. II. Masses and Radii", 2004, Ap.J., 609, 885, Mohanty, Jayawardhana, Basri.

J94. "First Determination of the Dynamical Mass of a Binary L Dwarf", 2004, A&A, 423, 341, Bouy, Duchêne, Köhler, Brandner, Bouvier, Martín, Ghez, Delfosse, Forveille, Allard, Baraffe, Basri, Close, McCabe.

J95. "Astrometric Monitoring of the Binary Brown Dwarf DENIS-P J1228.2-1547", 2004, A&A, 428, 205, Brandner, Martín, Bouy, Köhler, Delfosse, Basri, Andersen.

J96. "The T Tauri Phase Down to Nearly Planetary Masses: Echelle Spectra of 82 Very Low-Mass Stars and Brown Dwarfs", 2005, Ap.J., 626, 498, Mohanty, Jayawardhana, Basri.

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J98. "The Magnetic Properties of an L Dwarf Derived from Simultaneous Radio, X-Ray, and H-alpha Observations", 2005, A&A, 627, 960, Berger, Rutledge, Reid, Bildsten, Gizis, Liebert, Martín, Basri, et al.

J99. "Discovery of an M4 Spectroscopic Binary in Upper Scorpius: A Calibration Point for Young Low-Mass Evolutionary Models", 2005, Ap.J., 634, 1346, Reiners, Basri, Mohanty.

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J102."Measuring Magnetic Fields in Ultracool Stars and Brown Dwarfs", 2006, Ap.J., 644, 497, Reiners, Basri

J103. "Resolved HST Spectroscopy of Ultracool Binary Systems", 2006, A&A, 456, 253, Martín, Brandner, Bouy, Basri, Davis, Deshpande, Montgomery.

J104. "Stellar and Molecular Radii of a Mira Star: First Observations with the Keck Interferometer Grism", 2007, Ap.J.Lett. 645, L77, Eisner, Graham, Akeson, Ligon, Colavita, Basri, Summers, Ragland, Booth.

J105. "The First Direct Measurements of Magnetic Field on Very Low-Mass Stars" 2007, Ap.J. 656, 1121, Reiners, Basri.

J106. "A Re-appraisal of the Habitability of Planets Around M Dwarf Stars", 2007, Astrobiology 7, 30, Tarter, Backus, Mancinelli, Aurnou, Backman, Basri, Boss, Clarke, Deming, Doyle, and 22 others.

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J109. "Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. I. The Complex Behavior of the M8.5 Dwarf TVLM513-46546", 2008, Ap.J.673, 1080, Berger, Gizis, Giampapa, Rutledge, Liebert, Martin Basri, Fleming, Johns-Krull, Phan-Bao, Sherry.

J110. "Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. II. Mixed Trends in VB10 and LSR1835+32 and the Possible Role of Rotation", 2008, Ap.J. 676, 1307, Berger, Basri, Gizis, Giampapa, Rutledge, Liebert, Martin, Fleming, Johns-Krull, Phan-Bao, Sherry.

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J113. "Structural and compositional properties of brown dwarf disks: the case of 2MASS J04442713+2512164", 2008, A&A, 486, 877, Bouy, Huélamo, Pinte, Olofsson, Barrado, Martín, Pantin, Monin.

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J117. "Evidence for Magnetic Flux Saturation in Rapidly Rotating M Stars", 2009, Ap.J., 692, 583, Reiners, Basri.

J118. "On the magnetic topology of partially and fully convective stars", 2009, A&A, 496, 787, Reiners, Basri.

J119. "A First Look at Rotation in Inactive Late-Type M Dwarfs", 2009, Ap.J., 693, 1283, West, Basri.

J120. "Surprisingly Weak Magnetism on Young Accreting Brown Dwarfs", 2009, Ap.J., 697, 73, Reiners, Basri, Christensen.

J121. "Kepler’s Optical Phase Curve of the Exoplanet HAT-P-7b", 2009, Science 325, 709, Borucki, Koch, Jenkins, Sasselov, Gilliland, Batalha, Latham, Caldwell, Basri, Brown, and 15 coauthors.

J122. "A Volume-Limited Sample of 63 M7-M9.5 Dwarfs. I. Space Motion, Kinematic Age, and Lithium", 2009, Ap.J., 705, 1416, Reiners, Basri.

J123. "Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. III. X-ray, Radio, and H-alpha Activity Trends in M and L Dwarfs", 2009, Ap.J., 709, 332, Berger, Basri, Fleming, Giampapa, Gizis, Liebert, Martin, Phan-Bao, Rutledge.

J124. "Kepler’s Optical Phase Curve of the Exoplanet HAT-P-7b", 2009, Science, 325, 709, Borucki, Koch, Jenkins, and Kepler Team.

J125. "A Volume-Limited Sample of 63 M7-M9.5 Dwarfs. II. Activity, Magnetism, and the Fade of the Rotation-Dominated Dynamo”, 2010, Ap.J., 710, 924, Reiners, Basri.

J126. "Photometric Variability in Kepler Target Stars: The Sun Among Stars -- A First Look”, 2010, Ap.J., 713, L155, Basri, Walkowicz, Batalha, Gilliland, Jenkins, Borucki, Koch, Caldwell, Dupree, Latham, Meibom, Howell, Brown.

J127. "Kepler-4b: Hot Neptune-Like Planet of a G0 Star Near Main-Sequence Turnoff ", 2010, Ap.J., 713, L126, Borucki, Koch, Brown, and Kepler Team.

J128. "Kepler-7b: A Transiting Planet with Unusually Low Density”, 2010, Ap.J., 713, L140, Latham, Borucki, Koch, and Kepler Team.

J129. "Kepler Mission Design, Realized Photometric Performance, and Early Science”, Ap.J., 713, L79, Koch, Borucki, and Kepler Team.

J130. "Kepler Observations of Transiting Hot Compact Objects”, Ap.J., 713, L79, Rowe, Borucki, Koch, and Kepler Team.

J131. "Kepler Planet-Detection Mission: Introduction and First Results", 2010, Science, 327, 977, Borucki, Koch, and Kepler Team.

J132. "Discovery and Rossiter-McLaughlin Effect of Exoplanet Kepler-8b”, 2010, Ap.J., 724, 1108, Jenkins, Borucki, Koch, and Kepler Team.

J133. "Rotation and Magnetic Activity in a Sample of M-Dwarfs”, 2010, A.J., 139, 504, Browning, Basri, Marcy, West, Zhang.

J134. "On the Kinematic Age of Brown Dwarfs: Radial Velocities and Space Motions of 43 nearby L dwarfs”, 2010, A&A512, 37, Seifahrt, Reiners, Almaghrbi, Basri.

J135. "Kepler-9: A System of Multiple Planets Transiting a Sun-Like Star, Confirmed by Timing Variations", 2010, Science, 330, 51, Holman, Fabrycky, and Kepler Team.

J136. "Photometric Variability in Kepler Target Stars. II. An Overview of Amplitude, Periodicity, and Rotation in First Quarter Data”, 2011, A.J., 141, 20, Basri, Walkowicz, and Kepler Team.

J137. "White-light Flares on Cool Stars in the Kepler Quarter 1 Data”, 2011, A.J., 141, 50, Walkowicz, Basri, and Kepler Team.

J138. "Characteristics of Kepler Planetary Candidates Based on the First Data Set”, 2011, Ap.J., 728, 117, Borucki, Koch, and Kepler Team.

J139. "Kepler's First Rocky Planet: Kepler-10b”, 2011, Ap.J., 729, 27, Batalha, Borucki, and Kepler Team.

J140. "A First Comparison of Kepler Planet Candidates in Single and Multiple Systems”, 2011, Ap.J., 732, L24, Latham, Rowe, Quinn, Batalha, and Kepler Team.

J141. "The Kepler Cluster Study: Stellar Rotation in NGC 6811”, 2011, Ap.J., 733, L9, Meibom, Barnes, Latham, and Kepler Team.

J142. "Characteristics of Planetary Candidates Observed by Kepler. II. Analysis of the First Four Months of Data”, 2011, Ap.J., 728, 117, Borucki, Koch, and Kepler Team.

J143. "Kepler Mission Stellar and Instrument Noise Properties”, 2011, Ap.J.Supp., 197, 6, Gilliland, Chaplin, and Kepler Team.

J144. "Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler”, 2012, Ap.J.Supp., 201, 15, Howard, Marcy, and Kepler Team.

J145. "Planetary Candidates Observed by Kepler. III. Analysis of the First 16 Months of Data”, 2013, Ap.J.Supp., 204, 24, Batalha, Rowe, and Kepler Team.

J146. "The Information Content in Analytic Spot Models of Broadband Precision Light Curves”, 2013, Ap.J.Supp., 205, 17, Walkowicz, Basri, Valenti.

J147. "Comparison of Kepler Photometric Variability with the Sun on Different Timescales'', 2013, Ap.J., 769, 37, Basri, Walkowicz, Reiners.

J148. "An observational correlation between stellar brightness variations and surface gravity'', 2013, Nature, 500, 427, Bastien, Stassun, Basri, Pepper.

J149. "Rotation and differential rotation of active Kepler stars'', 2013, A&A, 560, 4, Reinhold, Reiners, Basri.

J150. "Rotation periods, variability properties and ages for Kepler exoplanet candidate host stars'', 2013, MNRAS, 436, 1883, Walkowicz, Basri.

J151. "Radial Velocity Variations of Photometrically Quiet, Chromospherically Inactive Kepler Stars: A Link between RV Jitter and Photometric Flicker'', 2014, A.J., 147, 29, Bastien, Stassun, Pepper, Wright, Aigrain, Basri, Johnson, Howard, Walkowicz.

J152. "Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets”, 2014, Ap.J.Supp., 210, 20, Marcy, Isaacson, Howard, Rowe, and Kepler Team.

J153. “Magnetospherically driven optical and radio aurorae at the end of the stellar main sequence”, 2015, Nature, 523, 568, Hallinan, Littlefair, Cotter, Bourke, Harding, Pineda, Butler, Golden, Basri and 6 more.

J154. “A Granulation `Flicker’-based Measure of Stellar Surface Gravity”, 2016, Ap.J., 818, 43, Bastien, Stassun, Basri, Pepper.

J155. “ Discovery of a Group of Receding, Variable Halo Stars toward Norma ”, 2017, Ap.J., 844, 159, Chakrabarti, Angeloni, Freeman, Sargent, Simon, and 11 authors including Basri.

J156. “Double Dipping: A New Relation between Stellar Rotation and Starspot Activity”, 2018, Ap.J., 863, 190, Basri and Nguyen

J157. “Calibration of Differential Light Curves for Physical Analysis of Starspots”, 2018, Ap.J., 865, 142, Basri.

J158. “Double-dipping to refine stellar rotation periods”, 2020, Astron. Notes, 341, 513, Tan and Basri.

J159. “The Information Content in Analytic Spot Models of Broadband Precision Light Curves. II. Spot Distributions and Lifetimes and Global and Differential Rotation”, 2020, Ap.J., 901, 14, Basri and Shah.

Invited Reviews and Commentary (usually refereed)

R1. "Stellar Activity: Cause and Effects", 1986, Protostars and Molecular Clouds, College de France and Commissariat à l'Energie Atomique (Montmerle and Bertout, eds.), 211, Basri.

R2. "The T Tauri Stars", 1987, Fifth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Linsky and Stencel eds., (Springer-Verlag), 411, Basri.

R3. "High Quality Echelle Observations of T Tauri Stars", 1987, IAU Symp. #132, Cayrel de Strobel & Spite, eds., (Kluwer Academic Publishers), 99, Basri.

R4. "Emission Activity on T Tauri Stars", 1988, NATO Advanced Study Institute on The Formation and Evolution of Low Mass Stars, Viana do Castelo, Portugal, Kluwer Academic Publishers (Dupre & Lago, eds.), 247, Basri.

R5. "The Classical T Tauri Stars -- Young Solar Systems"", 1989, The Sun in Time, Matthews & Giampapa eds., (Tucson: Univ. of Arizona Press), 682, Bertout, Basri, Cabrit.

R6. "Disks Around T Tauri Stars", 1990, Structure and Emission Properties of Accretion Disks, Bertout, Collin, Lasota, Trahn Van, eds., (Editions Fronti`eres:France), 189, Basri.

R7. "Solar Systems in the Making", 1990, Nature News and Views, 346, 515, Basri.

R8. "Strong Emission Lines in T Tauri Stars", 1990, High Resolution Spectroscopy in Astrophysics (Mem. S.A. It.), Pallavicini ed., 707, Basri.

R9. "Properties and Models of T Tauri Stars", 1991, The Physics of Star Formation and Early Stellar Evolution, NATO-ASI Workshop, Lada and Kylafis eds., (Kluwer:Dordrecht), 649, Basri & Bertout.

R10."T Tauri Stars and Their Accretion Disks", 1993, Protostars and Planets III, Levy and Lunine eds., (Tucson: Univ. of Arizona Press), 543, Bertout & Basri.

R11."Early Hints on the Substellar Mass Function", 1997, Star Formation Near and Far (7th Astrophysics Conference), AIP Conf.Proc. 3, Holt & Mundy eds., 93, 228, Basri & Marcy.

R12."The Lithium Test for Young Brown Dwarfs", 1997, Brown Dwarfs and Extrasolar Planets, A.S.P. CS-134, Rebolo, Martín , Zapatero-Osorio eds., 394, Basri.

R13."Revealing the Brown Dwarf Population in the Pleiades Open Cluster", 1997, Brown Dwarfs and Extrasolar Planets, A.S.P. CS-134, Rebolo, Martín, Zapatero-Osorio eds., 51, Zapatero-Osorio et al.

R14."Lithium near the substellar boundary: a new age diagnostic", 1998, Cool Stars in Open Clusters and Associations: Magnetic Activity and Age Indicators, (Mem. S.A. It. 68), 917, Basri.

R15."Surveying Low Mass Stars with SALT: Newborn and Stillborn", 1998, Proc. of the SALT/HET Workshop: Capetown, South Africa, Sp. Publ. of the SAAO, Buckley ed., 127, Basri.

R16."Brown Dwarfs: The First Three Years", 1999, Astron. Gesellschaft: Reviews in Modern Astronomy 12, 101, Basri.

R17."Aspects of the Substellar Mass Function", 2000, From Extrasolar Planets to Cosmology: The VLT Opening Symposium, Bergeron and Renzini eds., (Springer:Berlin), 429, Basri.

R18."The Discovery of Brown Dwarfs", April 2000, Sci.Am. 282, 76, Basri.

R19."Spectroscopy of Inner Protoplanetary Disks and the Star-Disk Interface", 2000, Protostars and Protoplanets IV, Mannings, Boss, Russell eds., (Tucson: Univ. of Arizona Press), 457, Najita, Edwards, Basri, Carr.

R20."Observations of Brown Dwarfs", 2000, Ann.Rev.Astr.Ap. 38, 485, Basri.

R21."Rotation and Halpha Emission Above and Below the Substellar Boundary", 2000, Eleventh Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, A.S.P. CS-223, García-López, Rebolo, Zapatero-Osorio (eds.), 261, Basri.

R22."High Resolution Spectra of L-type Stars and Brown Dwarfs", 2000, Very Low Mass Stars and Brown Dwarfs, Rebolo and Zapatero-Osorio (eds.), Cambridge Univ. Press, p. 133, Basri, Allard, Hauschildt, Mohanty.

R23."Ultra-Cool Very Low-Mass Binaries", 2001, The Formation of Binary Stars, IAU Symp. 200 (Zinnecker & Mathieu, eds. ASP), p. 55, Martín, Basri.

R24. "Young Stars in the Solar Neighborhood'', 2001, Nature News and Views, 411, 145, Basri.

R25. "Magnetic Activity and Rotation in Brown Dwarfs and Low Mass Stars", 2003, IAU Symp. 211, Martín (ed.), p. 427, Basri, Mohanty.

R26. "Rotation and Magnetic Activity in Brown Dwarfs", 2003, IAU Symp. 215, (Maeder & Eenens, Eds.), p. 248, Basri.

R27. "What is a Planet?", 2003, Mercury 32, 27, Basri.

R28. "Brown Dwarfs: Up Close and Physical", 2004, Plenary Lecture, BAAS, 203, 7402, Basri.

R29. "Magnetic Activity at the Low Mass Limit", 2004, IAU Symp. 219, p. 157, Basri.

R30. "Extrasolar Planets: Too Close for Comfort'', 2004, Nature News and Views, 430, 24, Basri.

R31. "Cooler than Cool: A Decade of Brown Dwarfs'', 2005, Sky and Telescope, 109, 34, Basri.

R32. "The Kepler Mission: A Wide-field Transit Search for Terrestrial Planets", 2005, New Astron. Rev., 49, 478, Basri, Borucki, Koch.

R33. "Planetesimals to Brown Dwarfs: What is a Planet?", 2006, Ann. Rev. Earth & Planetary Sci., 34, 193, Basri, Brown.

R34. "T Tauri Stars: From Mystery to Magnetospheric Accretion", 2007, IAU Symp. 243, p.13, Basri.

R35. "The Kepler Mission: Terrestrial Extrasolar Planets and Stellar Activity", 2008, Fourteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, A.S.P. CS-384, 281, Basri, Ramos-Stierle, Soto, Lewis, Reiners, Borucki, Koch.

R36. "Magnetic Activity in the Fully Convective Domain", 2009, Fifteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, AIPC 1094, 206, Basri.

R37. "The Discovery of the First Lithium Brown Dwarf: PPl 15", 2014, 50 Years of Brown Dwarfs,(Joergens, Ed.) Astrophysics and Space Science Library, 401, 51, Springer:Switzerland, Basri.

R38. "The Solar-Stellar Connection", 2019, The Sun as a Guide to Stellar Physics,(Engvold, Vial, Skumanich, Eds.) 363, Elsevier:Netherlands, Basri.

R39. " Astro2020: Promoting Diversity and Inclusion in Astronomy Graduate Education: an Astro2020 APC White Paper by the AAS Taskforce on Diversity and Inclusion in Astronomy Graduate Education ", 2019, arXiv 1907.06769, Rudolph, Basri, Agueros, Bertschinger, Coble, Donahue, Monkiewicz, Speck, Ivie, Pfund, Posselt.

Conference Proceedings and Other Publications

C1. "Partial Coherent Scattering in the Wings of Lyman-alpha", Proceedings of the Nov. 7-10, 1977 OSO-8 Workshop, Hansen and Schaffner eds., LASP, p. 29, 1977, with Roussel-Dupre.

C2. "High Resolution Absolute Flux Profiles of the Mg II h and k lines in Evolved F8-M5 Stars", 1980, The Universe at Ultraviolet Wavelengths: The Second Year of IUE, Chapman (ed.), 371, with Stencel, Mullan, Linsky.

C3. "On the Enigma of FK Comae," Proc. of the 2nd Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Vol. I, 1982, p. 219, Giampapa and Golub eds., with Walter.

C4. "Comparative Chromospheric and Coronal Emission from Close Binaries," Proc. of the 2nd Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Vol. II, 1982, 87, Giampapa and Golub eds., with Walter, Laurent.

C5. "The Chromospheric Rotation-Activity Relation in Late-type Close Binary Systems", The Universe at Ultraviolet Wavelengths: Four Years of IUE Research, 1982, p.566, Kondo et al. eds., with Walter, Laurent.

C6. "The Geometrical Structure of Activity in the AR Lac System", Highlights of Astronomy 6, 1983, 650, West ed., with Gibson, Walter.

C7. "Period-activity Relations in Close Binary Systems", IAU Symp. #102, 1983, p.199, Stenflo ed., with Laurent and Walter.

C8. "Activity Correlations in Close Binary Systems", Activity in Red Dwarf Stars, 1983, p.439, Byrne and Rodono eds., with Laurent.

C9. "Temperature Measurements of Hot DA White Dwarfs with IUE", The Future of UV Astronomy: Six Years of IUE, NASA Conf. Spec. Publ. 2349, 277, 1984 with Finley, Bowyer.

C10."T Tauri Stars: Through the Looking Glass", 1985,The Messenger42, 20, with Finkenzeller.

C11."Rossby or not Rossby", 1986, Fourth Cambridge Workshop on Cool Stars Stellar Systems, and the Sun,Zeilik ed., 184.

C12."Calibrated High Resolution Full Spectral Coverage of T Tauri Stars", 1986,Fourth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Zeilik ed., 442, with Finkenzeller.

C13."The Circumstellar Environment of Quiet T Tauri Stars", IAU Symp. #122, 1986, 103, with Finkenzeller.

C14."Magnetic Field Measurements on Late-type Stars: A New Technique", 1987, IAU Symp. #132, Cayrel de Strobel and Spite (eds.), 301, Kluwer Academic Publishers, with Marcy.

C15."Observation of Interstellar Absorption Lines Toward Hot White Dwarfs" 1988, Proceedings of ESA: A Decade of UV Astronomy with IUE, 350, with Jelinsky, Bowyer.

C16."Limits on the Magnetic Flux of a pre-main sequence star", 1991, The Sun and Cool Stars: activity, magentism, dynamos,Tuominen, Moss, Rüdiger, eds.), (Springer-Verlag:Berlin), p.401, with Marcy.

C17."Stellar Zeeman Analyses: Effects of multi-component atmospheres", 1991, The Sun and Cool Stars: activity, magentism, dynamos,Tuominen, Moss, Rüdiger, eds.), (Springer-Verlag:Berlin), p.407, with Marcy, Valenti.

C18."The Spectral Variability of BP Tauri", Eighth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, 1994, 729, Caillault (ed.), A.S.P. CS-64, with Simon, Imhoff, Ayres.

C19."A Search for Periodicities in Balmer Line Profiles of 6 T Tauri Stars", Eighth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, 1994, 190, A.S.P. CS-64, Caillault (ed.), with Valenti, Marcy.

C20."Stellar Population and Abundance Studies at High Resolution with Very Large Telescopes", 1995, P.A.S.P., 997, with Sneden, Boesgaard, Brown, Carney, Kraft, Smith, Suntzeff.

C21."Tests of Magnetospheric Accretion from Optical and UV Emission Lines in T Tauri Stars", 1996, Ninth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, A.S.P. CS-109, Pallavicini, (ed.), 419, with Calvet, Hartmann, Kwan, Valenti, Walter.

C22."EUVE and VLA Observations of the Eclipsing Pre-cataclysmic Variable V471 Tauri", 1996, Astrophysics in the Extreme Ultraviolet, IAU Colloq. 152, Bowyer and Malina (eds.), Kluwer:Dordrecht, p.349, with Cully, Dupuis, Rodriguez-Bell, et al.

C23."The Spectroscopic Variability of the T Tauri Star DF Tau", 1996, Ninth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, A.S.P. CS-109, Pallavicini, (ed.), 431, Johns-Krull & Basri.

C24."Rotation and Activity in the Coolest Stars", 1996, Ninth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, A.S.P. CS-109, Pallavicini, (ed.), 587, Basri, Oppenheimer, Kulkarni, Nakajima, Marcy.

C25."Is PPL 15 a Binary", 1997, Brown Dwarfs and Extrasolar Planets, A.S.P. CS-134, Rebolo, Martín, Zapatero-Osorio (eds.), 284, Basri & Martín .

C26."The First Line Profiles from Cool Field Brown Dwarfs", 1998, Tenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, A.S.P. CS-154, Donahue & Bookbinder (eds.), CD-1819, Basri, Martín , Ruiz, Delfosse, Forveille, Epchtein, Allard, Leggett.

C27."Approaching the Deuterium Burning Limit in the sigma Orionis Young Cluster", 2000, From Extrasolar Planets to Cosmology: The VLT Opening Symposium, Bergeron and Renzini (eds.),(Springer:Berlin), 446, Zapatero-Osorio, Béjar , Martín, Rebolo, Basri.

C28."Oxygen abundances derived in unevolved very metal poor stars", 2001, New Astronomy Reviews, 45, 519, García-López, Israelian, Rebolo, Bonafacio, Molaro, Basri, Shchukina.

C29."Stellar variability and its implications for photometric planet detection with Kepler", Proceedings of the First Eddington Workshop on Stellar Structure and Habitable Planet Finding, 2002, (Battrick, Favata, Roxburgh & Galadi, Eds.), ESA-SP 485, 35, Batalha, Jenkins, Basri, Borucki, Koch.

C30. "Abundances in Wide Binaries with Solar-Type Twin Components", IAU Symposium 219, 2003, p. 87, Pavlenko, Martín, Basri, Lyubchik.

C31. "Multiplicity of Nearby Free-floating Late M and L Dwarfs: HST-WFPC2 Observations of Candidates and Bona Fide Binary Brown Dwarfs", IAU Symp. 211, Martín (ed.), 2003, p. 245, Bouy, Brandner, Martín, Delfosse, Allard, Basri.

C32. "Very Low Mass Stars and Brown Dwarfs in Taurus", IAU Symp. 211, Martín (ed.), 2003, p.143, White, Basri.

C33. "Nomenclature: Brown Dwarfs, Gas Giant Planets, and ?", IAU Symp. 211, Martín (ed.), 2003, p. 529, Boss, Basri, Kumar, Liebert, Martín, Reipurth, Zinnecker.

C34. "Gravity & Mass Measurement in Young Substellar Objects", Frontiers of High Resolution Spectroscopy, 2003, 25th meeting of the IAU, Joint Discussion 20, p. 29, Mohanty, Basri, Jayawardhana, Allard, Hauschildt, Ardila.

C35. "The Kepler Mission: Finding the Sizes, Orbits and Frequencies of Earth-size and Larger Extrasolar Planets", Scientific Frontiers in Research on Extrasolar Planets, 2003, ASP Conf. Ser. 294, (Drake and Seager, eds.), p. 427, Borucki, Koch, Basri, Caldwell and 10 others.

C36. "The Kepler mission: a wide-field-of-view photometer designed to determine the frequency of Earth-size planets around solar-like stars", Future EUV/UV and Visible Space Astrophysics Missions and Instrumentation, (Blades and Siegmund, eds.), 2003, SPIE 4854, 129, Borucki, Koch, Lissauer, Basri, Caldwell and 8 others.

C37. "Accretion, Jets, and Disk-locking in the Brown Dwarf Domain'', 2005, Mem.S.A.It., 76, 303, Mohanty, Jayawardhana, Basri.

C38. "Accretion Disks in the Substellar Regime'', 2005, Mem.S.A.It., 76, 295, Jayawardhana, Mohanty, Basri.

C39. "Lithium depletion in the brown dwarf binary GJ 569Bab'', 2005, Astron. Nachr., 326, 948, Zapatero Osorio, Martín, Lane, Pavlenko, Bouy, Baraffe, Basri.

C40. "Accretion in brown dwarfs down to nearly planetary masses", 2005, Astron. Nachr., 326, 891, Mohanty, Basri, Jayawardhana.

C41. "Measuring physical properties of very young brown dwarfs'', 2006, Astron. Nachr., 327, 3, Basri.

C42. "The Kepler Mission: Astrophysics and Eclipsing Binaries", 2006, Ap&SS, 304, 391, Koch, D. Borucki, W. Basri, G. Brown, T. Caldwell, D. Christensen-Dalsgaard, J. Cochran, W. Dunham, E. Gautier, T. N. Geary, J and 6 others.

C43. "The Role of Convection in Brown Dwarfs", 2006, IAU Symp. 239, 15, Mohanty, Baraffe, Chabrier, Basri.

C44. "The Kepler Mission and Binary Stars", 2007, IAU Symp. 240, 21, Koch, Borucki, Basri, Brown, Caldwell, Cochran, Dunham, Gautier, Geary, Gilliland, and 5 others.

C45. "Dynamo Action in Fully Convective Low-Mass Stars", 2007, Unsolved Problems in Stellar Physics, AIPC 948, 157, Browning, Basri.

C46. "Finding Earth-size planets in the habitable zone: the Kepler Mission", 2008, IAU Symp. 249, 21, Borucki, Koch, Basri, Batalha, Brown, Caldwell, Christensen-Dalsgaard, Cochran, Dunham, Gautier, and 7others.

C46. "Activity and rotation of low mass stars in young open clusters", 2009, Fifteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, AIPC 1094, 373, Seifahrt, Reiners, Scholz, Basri.

C47. "Rotation and Activity in Late-type M Dwarfs", 2009, Fifteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, AIPC 1094, 700, West, Basri.

C48. "Saturation of Magnetic Flux Generation at low Rossby Numbers: The M Stars", 2009, Fifteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, AIPC 1094, 728, Seifahrt, Reiners, Scholz, Basri.

C49. "Dynamos and magnetic fields of the Sun and other cool stars, and their role in the formation and evolution of stars and in the habitability of planets", 2009, Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers, no. 262, Schrijver, Carpenter, Karovska, Ayres, Basri, Brown, Christensen-Dalsgaard, Dupree, Guinan, Jardine, and 7 coauthors.

C50. "Understanding Activity in Low Mass Stars", 2009, Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers, no. 30, Browning, Walkowicz, West, Basri, Kowalski, Hilton, Bouchanski.

C51. "First thoughts on stellar variability from Kepler commissioning data", 2010, IAU Symp. 264, 469, Walkowicz, Basri.

C52. "Kepler Light Curves and Stellar Rotational Periods", 2011, Sixteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, ASPC 448, 1033, Reinhold, Reiners, Basri, Walkowicz.

C53. "Starspots and Stellar Rotation: Stellar Activity with Kepler", 2011, Sixteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, ASPC 448, 177, Walkowicz, Basri.

C54. "Rotation & differential rotation of the active Kepler stars", 2014, Magnetic Fields throughout Stellar Evolution, IAU Symposium 202, 216,Reinhold, Reiners, Basri.

C55. “Increasing Diversity in Earth and Space Sciences”, 2015, Celebrating Science: Putting Education Best Practices to Work (Schultz, Burner, Shore, Barnes, eds.) ASPC 500, 7, Meinke, Ali, Shackelford, Mendez, Acevedo, Basri, Kenney, Lee.

C56. "Starspots and Stellar Rotation: Stellar Activity with Kepler", 2011, Sixteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, ASPC 448, 177, Walkowicz, Basri.

C57. "Rotation-Activity-Age Relations for Solar-type and Cooler Stars", 2016, Nineteenth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, id.17, Basri.

C58. "What is Kepler Really Telling Us about Starspots", 2018, Twentieth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, http://coolstars20.cfa.harvard.edu/ , cs20, id.73 , Basri.

Abstracts

A1. "Preliminary Analysis of NRL Rocket Spectra of the Lyman-alpha Line Wings", 1976, B.A.A.S. 8, 331, with Bartoe, Brueckner, Linsky, VanHoosier.

A2. "Simultaneous High-dispersion Stellar Spectroscopy with Copernicus and the McMath Solar Telescope", 1976, B.A.A.S. 8, 353, with Maran, Chiu, Linsky, Henry, Moos, McClintock.

A3. "Model Chromospheres and Photospheres of Selected G and K Giants", 1976, B.A.A.S. 8, 518, with Kelch, Linsky, Chiu, Maran, Furenlid.

A4. "Models of Solar Chromosphere Structures Implied by Lyman-alpha Rocket Spectra", 1976, B.A.A.S. 8, 534, with Linsky, Bartoe, Brueckner, VanHoosier.

A5. "Evidence for Outward Acceleration of the Circumstellar Shell of alpha Orionis Determined by High Resolution Vidicon Spectroscopy", 1977, B.A.A.S.9, 345, with Linsky, Chiu, Chang, Maran.

A6. "A First Look at IUE Far Ultraviolet Spectra of K and M Stars - alpha Ori, alpha Boo, and epsilon Eri", 1978, B.A.A.S. 10, 443, with Linsky.

A7. "Model Chromospheres for Supergiants: A Progress Report", 1979, B.A.A.S.10, 647, with Linsky.

A8. "Resonance Line Formation and the Wilson-Bappu Effect", 1979, B.A.A.S.11, 472.

A9. "Formation of Strong Resonance Line Wings", 1980, B.A.A.S.11, 625.

A10."The Chromospheric Explanation of T Tauri Spectra", 1980, B.A.A.S.12, 520, with Calvet, Kuhi.

A11."High Resolution Spectra of Five Late-Type Dwarfs and Giants Obtained with the IUE Satellite", 1981, B.A.A.S. 13, 546, with Ayres, Henry, Landsman, Linsky, Moos, Stencel.

A12."The Unusual Outer Atmosphere of 56 Peg", 1981, B.A.A.S. 13, 547, with Schindler, Stencel, Linsky, Helfand.

A13."He II in the Spectrum of the Hot White Dwarf HZ43: Photospheric or Interstellar"", 1981, B.A.A.S. 13, 873, with Malina, Bowyer.

A14."Evidence for Photospheric Soft X-ray Emission from Sirius B", 1981, B.A.A.S. 13, 810, with Martin, Lampton, Kahn.

A15."The Relation between Coronal, Chromospheric, and Magnetic Activity: A Case Study", 1981, B.A.A.S. 13, 828, with Walter, Marcy.

A16."The Structure of the Coronae of AR Lacertae", 1981, B.A.A.S.13, 833, with Walter, Gibson.

A17."Coordinated Multi-spectral Coverage of T Tauri Stars", 1983, Proc. of Haro Symposium, Rodriguez (ed.), (Mexico City), with Kuhi.

A18."A Straightforward Search for the Solar Companion", 1985, The Galaxy and the Solar System Matthews (ed.), (Univ. of Arizona Press:Tucson), with Bowyer.

A19."A Transition between Chromosphere and Wind for MgII in T Tauri Stars", 1985, B.A.A.S. 16, 938, with Calvet, Imhoff, Giampapa.

A20."Improved Analysis of Stellar Magnetic Fields",1986, B.A.A.S.18, 984, with Marcy.

A21."Upper Limits to Ultraviolet Line Emission in Fully Convective M Dwarfs", Proc. of the XXVI COSPAR Conf., Toulouse, France, with Ambruster.

A22."A Catalog of MgII Emission Line Fluxes for T Tauri Stars", 1987, B.A.A.S.19, 728, with Imhoff, Giampapa.

A23."Photospheric Activity in Cool Main Sequence Stars", 1988, B.A.A.S.20, 696, with Wilcots, Stout.

A24."Observations of Young Stars", 1989, B.A.A.S. 20, 1034.

A25."Synoptic Observations of RW Aur", 1989, B.A.A.S. 21, 716, with Stout.

A26."Strong Emission Lines in T Tauri Stars", 1989, B.A.A.S. 21, 716, with Rumph, Batalha, Stout.

A27."Optical Veiling from Accretion onto T Tauri Stars", 100th Anniversary, Astr. Soc. Pacific, Berkeley, June 1989, with Batalha.

A28."Wild Spectral Variations in DF Tau", 1989, B.A.A.S. 21, 1084, with Misch.

A29."The Temperature Scale of Hot DA White Dwarfs Based on FUV Spectrophotometry", 1989, B.A.A.S. 21, 1102, with Finley, Bowyer.

A30."Synoptic Spectroscopic Observations of T Tauri Stars", Protostars and Planets III, Tucson, Mar. 1990, with Salter, Giampapa.

A31."Probing the Early Evolution of Solar-type Stars: Lithium Abundances", 3rd International Bioastronomy Symposium, Val Cenis, Savoie, with Martin, Bertout.

A32."Violent Variability in the Young Sun and Solar Nebula: Case Studies from the T Tauri Stars", 54th Meeting of the Meteoritical Society, July 1991.

A33."Direct Measurement of Magnetic Fields on T Tauri Stars", Seventh Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Tucson, Oct. 1991, with Marcy.

A34."The He I D 3 Line in T Tauri Stars", 1992, B.A.A.S.24, 1288, with Stout, Batalha.

A35."Balmer Jumps in T Tauri Stars", 1992, B.A.A.S. 24, 1288, with Valenti.

A36."Magnetic Fields on epsilon Eri from High Quality FTS Spectra near 1.6 microns", 1993, B.A.A.S.25, 875, with Valenti, Marcy.

A37."A Remarkable FUV Flare on the Pleiades G Dwarf HZ 314", 1993, B.A.A.S.25, 875, with Ayres, Stauffer, Simon, Stern, Antiochos, Bookbinder, Brown, Doschek, Linsky, Ramsey, Walter.

A38."High Resolution Spectroscopy in the Non-thermal Infrared: Use of an existing Coudé system", 1993, B.A.A.S. 25, 886, with Marcy.

A39."High Resolution Spectral Variability of SU Aur", 1993, B.A.A.S.25, 904, with Johns.

A40."Multiline Modeling of T Tauri Star Winds", 1993, Cosmic Winds, with Johns.

A41."GHRS Profiles of Hot UV Lines in T Tauri Stars", 1993, B.A.A.S.25, 1351, with Valenti, Walter, Hartmann, Calvet.

A42."A Keck Search for Lithium in a Brown Dwarf Candidate", 1994, First Science with Keck, meeting at UCSD.

A43."Keck HIRES at the Bottom of the Main Sequence", 1994, High Resolution Spectroscopy with Very Large Telescopes, Tucson.

A44."The T Tauri Double--Lined Spectroscopic Binary DQ Tau", 1996, B.A.A.S., 27, with Stassun, Mathieu, Johns-Krull, Valenti, Jensen, Hartmann.

A45."Rapid Rotation Above and Below the Substellar Boundary", 1999, B.A.A.S., 29, Abs. #82.08.

A46."Stellar and Planetary Data Products Expected from the Kepler Mission", NASA Laboratory Astrophysics Workshop, May 1-3 2002, (F.Salama, Ed.), with Borucki, Kock, et al.

A47. "The Origin of X-rays in Pre-Main Sequence Stars", 2004, B.A.A.S., 205, Abs.#105.09, Stassun, Ardila, Barsony, Basri, Mathieu.

A48. "Opportunities for High Precision Photometric Measurements of Variable Stars: Kepler Guest Investigator Program", B.A.A.S., 205, Abs.#33.05, Borucki, Koch, Basri, Latham, Howell.

A49. "Continuum Contrast as a function of Magnetic Flux Density and Disk Position: Results from a full Solar Cycle of SOHO/MDI data", AGU Fall 2006, Abstract #SH11A-0373, Soto, Basri, Ramos-Stierle, Lewis, Reiners, Berger.

A50. "Sunspot Contrast Measurements from MDI Full-Disk Images: Variations with Disk Position and Solar Cycle Phase", AGU Fall 2006, Abstract #SH11A-0374, Lewis, Soto, Basri, Ramos-Stierle, Reiners, Berger.

A51. "Correction of MDI Full-Disk Magnetograms for Limb Angle Effects by the Assumption of Average Magnetic Uniformity", AGU Fall 2006, Abstract #SH11A-0375, Ramos-Stierle, Soto, Basri, Lewis, Reiners, Berger.

A52."Understanding Stellar Variability in Kepler Lightcurves", 2011, B.A.A.S., 218, Abs. #311.02, Basri.

A53."The Science in Science Fiction: Using Popular Entertainment as a Gateway", 2011, B.A.A.S., 218, Abs. #116.06, Basri.

A54."Harnessing the Power of NASA's Kepler Mission for Understanding Stellar Activity and Enhancing Planet Discovery", 2012, B.A.A.S., 219, Abs. #345.04, Bastien, Stassun, Pepper, Walkowicz, Basri, Carpenter.

A55."A Large Sample of Magnetically-Active Stars Observed With Kepler", 2013, B.A.A.S., 221, Abs. #354.15, Wells, Neff, Brown, Ayres, Basri, et al.

A56."Young Star Populations in the Kepler Field", 2013, B.A.A.S., 221, Abs. #354.14, Brown, Neff, Wells, et al.

A57.”Flicker, Jitter, Crackle: Lifting the Veil on Stellar Variability and Understanding its Impact on Planet Detection with Kepler", 2014, B.A.A.S., 223, Abs. #103.02, Bastien, Stassun, Basri, Pepper.

A58.”The Sun Among Stars: A Photometric Comparison from Kepler", 2015, IAU General Assembly, Meeting #29, Abs. #2255663, Basri.


Programme and abstracts

Click on a talk or poster title to view the abstract.

Monday 30 March

Download
09:00 - 10:00 Registration
10:00 - 10:05 Welcome address
10:05 - 10:20 Bill Chaplin Asteroseismology and Exoplanets at Birmingham
10:20 - 10:30 Stefan Lines Two&rsquos a crowd: the difficulties of circumbinary planet formation pdf
10:30 - 10:40 Gavin Coleman Forming low-mass compact planetary systems
10:40 - 10:50 Matthew Mutter The Effects of Disc Self-Gravity on Circumbinary Disc Evolution
10:50 - 11:05 Philip Carter Exoplanet research at the University of Bristol pdf
11:05 - 11:30 Coffee + posters
11:30 - 11:45 Didier Queloz Planet detection and characterisation
11:45 - 11:55 Aimée Hall Early results from reprocessing of the SuperWASP survey pdf
11:55 - 12:05 Joey Rodriguez The KELT Exoplanet Survey
12:05 - 12:15 Pamela Rowden False positives and shallow eclipsing binaries pdf
12:15 - 12:25 Oliver Turner Targeting Bright Stars with SuperWASP-South pdf
12:25 - 12:35 Maximilian Guenther Expected Yield of Planets and False Positives in Transit Surveys
12:35 - 12:50 Mark Wyatt Exoplanet research at the IoA Cambridge
12:50 - 14:00 Lunch + posters
14:00 - 14:15 Richard Wilson Developments at Durham CfAI for characterisation and correction of scintillation noise in high-precision photometry
14:15 - 14:30 Hannu Parviainen Search for secondary eclipses in Kepler light curves
14:30 - 14:45 David Brown Constraints on circumbinary planet orbits from Kepler single transit events pdf
14:45 - 15:00 Tiffany Kataria The atmospheric circulation of hot Jupiters in the WASP sample
15:00 - 15:15 Brice-Olivier Demory Variability in the atmosphere of a super-Earth exoplanet
15:15 - 15:30 Beth Biller Exoplanets and Astrobiology at Edinburgh
15:30 - 16:00 Coffee + posters
16:00 - 16:15 Annelies Mortier Earth-like exoplanet signals hidden by stellar activity pdf
16:15 - 16:30 Heather Cegla Spectral Line Variability in Exoplanet Host Stars: Disentangling Planetary Signatures
16:30 - 16:45 Raphaelle Haywood Exploring the Sun&rsquos activity-driven radial-velocity variations to improve exoplanet detections
16:45 - 17:00 James Osborn Scintillation noise on Large and Extremely Large telescopes pdf
17:00 - 17:15 John Young The Planet Formation Imager
17:15 - 17:30 Mariangela Bonavita On the Gaia-SPHERE Synergy for Improved Characterization of the Orbital Architecture of Wide-Separation Giant Planet Systems
17:30 - 17:45 Isabelle Baraffe Exoplanets made in Exeter: detection, characterisation and modelling pdf
17:45- 17:55 Alexander Mustill The destruction of inner planetary systems during the high-eccentricity migration of gas giants pdf
19:00 Dinner Location: Rootes restaurant, Rootes building
20:00 Cocktail reception

Tuesday 31 March

Download
09:00 - 09:15 Hugh Jones Exoplanet research at the University of Hertfordshire
09:15 - 09:25 Hannah Wakeford Transmission spectral properties of clouds in the atmospheres of hot Jupiter exoplanets pdf
09:25 - 09:35 Tom Louden High resolution transmission spectroscopy of HD 189733b
09:35 - 09:45 Gabriella Hodosán Lightning on exoplanets and brown dwarfs: What can we learn from Solar System analogies?
09:45 - 09:55 Jakub Bochinski Direct evidence for an evolving dust cloud from the exoplanet KIC 12557548 b pdf
09:55 - 10:10 Coel Hellier Exoplanet research at Keele University
10:10 - 10:20 Will McLean Spectropolarimetry as a tool for the characterisation of exoplanets pdf
10:20 - 10:30 Dora Fohring Scintillation Noise in Exoplanet Transit Photometry
10:30 - 11:00 Coffee + posters
11:00 - 11:15 Richard Alexander Exoplanet research at the University of Leicester
11:15 - 11:30 Nikolay Nikolov HST Transmission Spectral Survey: A rather clear atmosphere of WASP-17b
11:30 - 11:45 John Barnes Starspot distributions on fully convective M dwarfs: implications for radial velocity planet searches
11:45 - 12:00 Tom Evans ExoMOS: a purpose-built instrument for characterising exoplanet atmospheres
12:00 - 12:15 Sarah Casewell Brown dwarfs in irradiated environments pdf
12:15 - 12:30 Eamonn Kerins Exoplanet research at Manchester
12:30 - 14:00 Lunch + posters
14:00 - 14:15 Tamara Rogers Exoplanet research at Newcastle University
14:15 - 14:25 Ahmed Al-Refaie Some like H2CO hot: The Exomol Project
14:25 - 14:35 Benjamin Drummond Fully Consistent Non-Equilibrium Chemistry in hot Jupiter Atmospheres
14:35 - 14:45 Emma Barton Implementing Pressure Broadening in Molecular Line Lists for Application to Extrasolar Planets
14:45 - 14:55 Paul Rimmer A Chemical Kinetics Network for Lightning on Planetary and Exoplanetary Atmospheres
14:55 - 15:05 Graham Lee Nucleation and Cloud Formation in HD 189733b
15:05 - 15:15 Benjamin Pope The Palomar Kernel Phase Experiment
15:15 - 15:30 Carole Haswell Exoplanet Research at the OU
15:30 - 16:00 Coffee + posters
16:00 - 16:15 Patrick Irwin Exoplanet research at the University of Oxford pdf
16:15 - 16:30 Guy Davies Time: the final, final frontier - Ageing exoplanet host stars pdf
16:30 - 16:45 Stephen Fendyke UV and X-ray Photoevaporation of Circumbinary Discs
16:45 - 17:00 Giovanni Rosotti The evolution of transition discs
17:00 - 17:15 Adrian Barker Tides in giant planets and stars
17:15 - 17:30 Christopher Watson Exoplanet research at Queen's University Belfast
17:30 - 17:40 Marco Rocchetto The frequency and infrared brightness of circumstellar discs at white dwarfs
19:00 Conference dinner Location: Chancellors Suite, Rootes building

Wednesday 1 April

Download
09:00 - 09:15 Richard Nelson Exoplanets research at QMUL
09:15 - 09:25 David Armstrong Planets and Variables with K2
09:25 - 09:35 Deepak Mahtani Semi-synthetic secondary eclipse lightcurves of hot Jupiter exoplanets
09:35 - 09:45 Jessica Spake WASP-135b and spin-orbit interactions in extreme systems
09:45 - 09:55 Edward Gillen Constraining the early stages of stellar evolution with eclipsing binaries
09:55 - 10:05 Thomas North Prospects for detecting planets around red-giant stars pdf
10:05 - 10:20 Christiane Helling Exoplanetary research in St Andrews
10:20 - 10:50 Coffee + posters
10:50 - 12:20 UK community + STFC session
12:20 - 13:50 Lunch + posters
13:50 - 14:05 Giovanna Tinetti Exoplanet research at University College London
14:05 - 14:15 Hugh Osborn New Discoveries from the WASP Archive
14:15 - 14:25 Daniel Staab Absorbing gas around a bright, mature F-star
14:25 - 14:35 David Wilson White Dwarfs As Probes Of The Chemistry Of Exo-planetary Systems pdf
14:35 - 14:45 Tim Pearce The orbits and dynamics of eccentric, long-period companions pdf
14:45 - 14:55 Eva Plávalová Do we need a system of classification for extrasolar planets? pdf
14:55 - 15:05 Clara Sousa Silva EduTwinkle
15:05 - 15:20 Peter Wheatley Exoplanet research at Warwick
15:20 - 15:50 Coffee + posters
15:50 - 16:05 Simon Walker A characteristic orbital period of giant planets from the WASP survey pdf
16:05 - 16:20 Grant Kennedy A wider view of planetary system alignment pdf
16:20 - 16:35 Eric Lopez The Evolution and Compositions of Sub-Neptunes and Super-Earths
16:35 - 16:50 Tom Hands There Might Be Giants
16:50 - 17:05 Dimitri Veras The growing field of post-main-sequence exoplanetary science
17:05 - 17:10 Concluding remarks

Posters

Name Title Download
Eleanor Bacchus Observing HD 114174 B as a demonstration of high contrast imaging spectroscopy with Project 1640
Emma Barton Implementing Pressure Broadening in Molecular Line Lists for Application to Extrasolar Planets
David Brown Constraints on circumbinary planet orbits from Kepler single transit events pdf
Heather Cegla Spectral Line Variability in Exoplanet Host Stars: Disentangling Planetary Signatures
Katy Chubb Three years of Exomol: new molecular line lists for exoplanet and other hot atmospheres
Rupert Dodkins MKIDs: next generation exoplanet detectors pdf
Amanda Doyle The influence of stellar macroturbulence on spectral lines pdf
Daniel Evans Stellar Companions to Exoplanet Host Stars in the Southern Hemisphere
Tom Evans ExoMOS: a purpose-built instrument for characterising exoplanet atmospheres
Ryan Garland Modelling the Spectra of Brown Dwarfs
Edward Gillen The first low-mass, pre-main sequence eclipsing binary with evidence of a circumbinary disk
Aimée Hall Early results from reprocessing of the SuperWASP survey pdf
Cassandra Hall Observational Signatures of Self Gravitating Protostellar Discs
Kirstin Hay Is the highly eccentric orbit of WASP-118b misaligned? pdf
Christina Hedges The Importance of Accurate Molecular Spectroscopy for Characterising Exoplanetary Atmospheres
James Kirk Transmission Photometry with ULTRACAM
Emma Longstaff Irradiated Brown Dwarfs
Pierre Maxted Bayesian mass and age estimates for transiting extrasolar planet host stars pdf
James McCormac The Next Generation Transit Survey
Will McLean Spectropolarimetry as a tool for the characterisation of exoplanets pdf
Ken Rice Disc fragmentation rarely forms planetary-mass bodies
Marion Neveu-VanMalle Two hot Jupiters from WASP with big brothers
Tim Pearce The orbits and dynamics of eccentric, long-period companions pdf
Saavidra Perera SCIDAR Scintillation Profiling and Exoplanet Transit Observations at Paranal
Eva Plávalová Do we need a system of classification for extrasolar planets? pdf
Joey Rodriguez Target Selection for the TESS Survey
Jean Teyssandier Torque on an exoplanet from an anisotropic evaporative wind
Scott Thomas Do you want to build a planet?
Samantha Thompson HARPS3 and the Terra Hunting Experiment

Abstracts

Ahmed F. Al-Refaie

Title:

Some like H2CO hot: The Exomol Project

Abstract:

The standard way of characterising the atmospheres of exoplanets and cool stars is through forward modelling. Forward modelling can infer the composition and temperature/pressure profile by producing a synthetic spectra that close matches those observed. Such modelling requires spectroscopic data of atoms and molecules relevant to these atmospheres. Temperature ranges of hot Jupiters and cool stars allow for a significant composition of molecules in their atmospheres. Molecules have extremely complex and rich spectral structures that become increasingly dense in transitions as their temperatures increase. Experimentally acquiring and assigning spectroscopic data at high temperatures and a wide range of frequencies can pose a wide range of challenges and difficulties. An alternative solution to this is to build the line-list through theoretical means, this is the goal of the Exomol project [1]. The Exomol project aims to provide a comprehensive line-list for a range of molecules at high temperatures relevant to exoplanets and cool stars. This talk will describe the process and challenges faced in producing our recent hot line-list AYTY [2] for the molecule formaldehyde. Production and refinement of the potential energy surface, solving the Schroedinger equation variationally using TROVE [3] and the evaluation of over 10 billion transitions will be discussed. Formaldehyde has a range of astrophysical phenomena that makes it interesting enough to be considered in the Exomol project. It is abundant in the interstellar medium (ISM)[4]. It is a precursor to many complex organic molecules in the ISM that include interstellar glycolaldehyde[5] and amino acids [6]. Multiple detections in comets [7] and proto-planetary discs [8]. Detection of masers in 19 extra-galactic sources [9] and finally, multiple early Earth models suggests it may act as a possible bio-marker [10,11].

[1] J. Tennyson and S. N. Yurchenko. MNRAS , 425, 21-33 , 2012 [2] A. F. Al-Rafaie, S. N. Yurchenko, A. Yachmenev, and J. Tennyson. MNRAS, 2015. [3] S. N. Yurchenko, W. Thiel, and P. Jensen. J. Mol. Spectrosc., 245, 126-140, 2007. [4] W. D. Langer. ApJ, 210, 328-333, 1976 [5] J. M. Hollis, F. J. Lovas, and P. R. Jewell. ApJ, 540, 107-L110, 2000. [6] W. A. Schutte. Adv. Space Res., 30, 1409-1417, 2002. [7] D. Bockelee-Morvan and J. Crovisier. . A&A, 264, 282-291, 1992. [8] K. I. Oberg et. al. ApJ, 720,480-493, 2010. [9] J. G. Mangum, J. Darling, K. M. Menten, and C. Henkel. ApJ, 673, 832-846, 2008. [10] M. Neveu, H. Kim, and S. A. Benner. Astrobiology, 13,391-403, 2013. [11] N. Goldman and I. Tamblyn. J. Phys. Chem. A, 117,5124-5131, 2013.

Richard Alexander

Presentation type: institutional summary

Title:

Exoplanet research at the University of Leicester

Abstract:

I will present a summary of the exoplanet research programme at the University of Leicester. I will give an overview of our on-going projects, spanning observational, theoretical and instrumental research, point out some recent highlights, and discuss the future direction(s) of our work on exoplanets.

David Armstrong

Title:

Planets and Variables with K2

Abstract:

With the recent revival of the Kepler spacecraft in the form of K2, we have a chance to find small planets around sometimes much brighter stars than allowed by the original mission, albeit on shorter periods. K2 presents its own challenges to detection, particularly from the motion of the spacecraft. I will describe some features of the K2 data, and show how we have been dealing with these to produce detrended K2 lightcurves at Warwick. I will also show some results for both planets and variable stars, and describe the state of our search for new candidate planets in the data.

Eleanor Bacchus

Title:

Observing HD 114174 B as a demonstration of high contrast imaging spectroscopy with Project 1640

Abstract:

Project 1640 is a direct imaging survey with the ability to simultaneously obtain images and low resolution spectra of faint companions around nearby stars. The spectra span the H and J bands in the near infrared and enable the detection of broad molecular absorption lines, allowing basic atmospheric modelling to be done and helping to characterise imaged companions. We are currently conducting a survey of near A-F type stars with the aim of detecting young, Jupiter mass planets at separations of around 1&rdquo-2&rdquo from their host stars.

We have also undertaken several observations of known companions, in order to both test our pipeline and provide spectra and further astrometric data to help refine photometric and orbital parameters for these objects. One of these is the TRENDS object HD 114174 B &ndash a faint white dwarf around a nearby G star. We present astrometry and spectroscopy of this object as an example of what can be achieved with a method that is going to play an important role in the future characterisation of exoplanets.

Isabelle Baraffe

Presentation type: institutional summary

Title:

Exoplanets made in Exeter: detection, characterisation and modelling

Abstract:

Adrian Barker

Title:

Tides in giant planets and stars

Abstract:

Tidal interactions between short-period planets and their host stars are thought to play an important role in the evolution of the planetary orbit and stellar spin. In particular, the fate of short-period planets is determined by the dissipation of tidal flows inside their stars, and the observational preponderance of circular orbits amongst short-period planets (relative to those with wider orbits) is thought to be explained by the dissipation of tidal flows inside these planets. I will review our current understanding of the mechanisms of tidal dissipation inside both planets and stars, and will present the results of recent and ongoing theoretical work aimed at understanding the mechanisms of tidal dissipation using simulations from first principles. The importance of various mechanisms in explaining the observations will be discussed.

John Barnes

Title:

Starspot distributions on fully convective M dwarfs: implications for radial velocity planet searches

Abstract:

Upcoming precision radial velocity surveys will search for low mass planets orbiting the lowest mass stars. The contribution of photospheric activity to astrophysical jitter must therefore be considered when characterising planetary radial velocity signatures. I will present Doppler images of the latest M dwarfs to date, GJ 791.2A (M4.5V) and LP 944-20 (M9V). The time series spectra of the stars reveal numerous line profile distortions which we interpret as starspots. Although starspot activity is stronger at high latitudes, we reconstruct spots distributed at a range of phases and latitudes. The low contrast and uniform distribution or absence of spots at low latitudes explain the relatively low amplitude photometric variability seen in M dwarfs. The reconstructed starspot patterns yield r.m.s. radial velocity jitter of order 100 m/s. Since M dwarfs in the M4.5-M9V spectral range exhibit mean vsini = 5-16 km/s, radial velocity surveys targeting this population will likely need to find methods to effectively remove starspot jitter.

Emma J Barton

Presentation type: talk and poster

Title:

Implementing Pressure Broadening in Molecular Line Lists for Application to Extrasolar Planets

Abstract:

ExoMol has previously calculated high resolution temperature dependent cross-sections for selected molecules according to Hill et al. (2013). Pressure dependence is now being implemented for five molecules expected to be of importance in the atmospheres of Hot Jupiter's, H2O, CO2, CO, CH4 and NH3.

Unfortunately there is an overall lack of accurate pressure broadening parameters for high temperature molecular lines and broadening by relevant species, namely H2 and He. For the most part parameters are extrapolated from room temperature and pressure and small quantum numbers or approximated using air broadening parameters given in HITRAN with the exception of H2O. For this molecule a data set of H2 and He pressure broadening parameters for molecular lines of importance in the temperature range 500 &ndash 2000 K has been computed by Nina Lavrentieva and Anna Dudaryonok using semi-empirical methods.

Presented is a summary of the work done to date including an investigation into the influence of pressure broadened width accuracy on Exoplanet spectral models using Tau-REx.

Beth Biller

Presentation type: institutional summary

Title:

Exoplanets and Astrobiology at Edinburgh

Abstract:

Over the last few years, we have been building a dynamic and growing exoplanets and astrobiology group at the University of Edinburgh. Dr. Ken Rice (along with postdoc Dr. Eric Lopez and PhD student Cassandra Hall) leads theoretical work regarding the formation and stability of planetary systems, including simulations of self-gravitating discs, the ultimate fate of self-gravitating disc fragments, the dynamical evolution of planetary systems, and the formation and evolution of super-Earths and sub-Neptunes. Dr. Beth Biller (along with postdoc Dr. Mariangela Bonavita and PhD student Johanna Vos) leads observational direct imaging studies of exoplanets, with a particular focus on the statistical analysis of large direct imaging exoplanet surveys, variability of young free-floating brown dwarfs and planets, and variability of exoplanet companions to young stars. Professor Charles Cockell is the director of the UK Centre for Astrobiology and leads a group studying life in extreme environments, in particular the interaction of microbes with minerals and the function and diversity of microbes in rocky environments. Professor Paul Palmer is a climate scientist specialising primarily in Earth atmosphere modeling, but is branching out into modeling of exoplanet and brown dwarf atmospheres along with PhD student Jack Yates.

Jakub Bochinski

Title:

Direct evidence for an evolving dust cloud from the exoplanet KIC 12557548 b

Abstract:

A super-mercury, known as KIC 12557548 b, has been hypothesised to be the source of the asymmetric and highly variable transit-like signature visible in the light curve of the star KIC 12557548. I will present simultaneous multi-colour optical photometry of this system obtained in July 2013 with ULTRACAM on the William Herschel Telescope. It reveals, for the first time, the colour dependence of the transit depth and provides direct evidence in favour of KIC 12557548 b being a disrupting low-mass rocky planet, feeding a transiting dust cloud. If the grain size in the transiting dust cloud changes as the transit depth changes, the extinction efficiency is expected to change in a wavelength- and composition-dependent way. Observing a change in the wavelength-dependent transit depth would offer an unprecedented opportunity to determine the composition of the disintegrating rocky body KIC 12557548 b.

Mariangela Bonavita

Title:

On the Gaia-SPHERE Synergy for Improved Characterization of the Orbital Architecture of Wide-Separation Giant Planet Systems

Abstract:

Even though giant planets represent the majority of the planets detected so far, we are far from having a clear picture of their occurrence, variety, and properties. RV and transit explorations are indeed still limited to planets in relatively close orbits, while current direct imaging searches probe the outermost regions of the planetary systems in the early phases of formation, when the planet/star contrast is favorable because young planets are still hot.

New and more precise dedicated instruments (such as SPHERE at the VLT and GPI at the GEMINI south) are becoming available and are expected to dramatically improve the number of detections of young planets in wide orbits. Imaging allows a comprehensive view of systems, determining planetary orbits and an extensive spectro-photometric characterization, but the mass determination of these planets relies on the prediction of the evolutionary models which provide a mass estimate given the age and the observed luminosity. These models are uncertain and have not been calibrated so far by means of observations. This requires independent dynamical measurements of the mass of the planets. Precise RV measurement are extremely difficult for the imaging targets, because of the high level of activity expected for these young stars, leaving astrometry the best possible way to obtain the needed dynamical constraints. The current precision for astrometric measurements is not high enough to achieve this goal, but the advent of the ESA Gaia satellite will very soon change this. Here we present results from a detailed set of numerical simulations (using actual target lists and synthetic planet populations) aimed at gauging the elements of the parameter space of orbital architectures and masses of wide-separation giant planet systems that might be constrained to a significant extent by combining SPHERE imaging and astrometric data and Gaia astrometry. We focus in particular on the characterization of systems detected by both instruments or in one channel only. The results are expressed in the form of metrics characterizing, for example, the achievable precision in mass determination from the combined techniques.

David Brown

Presentation type: talk and poster

Title:

Constraints on circumbinary planet orbits from Kepler single transit events

Abstract:

All of the known transiting circumbinary planets orbit very close to coplanar with their host binaries. But circumbinary systems are not, a priori, limited to this configuration misaligned systems are likely to exist, and their discovery and characterisation of would shed light on the dynamical history of planets on circumbinary orbits, and on the possible migration mechanisms that might be acting on such complex systems.

We have identified candidate misaligned circumbinary systems within Kepler data. These candidates show single, non-periodic transits that can be used to place constraints on possible orbital configurations for the third body for given binary star parameters. We have developed tools to identify and model possible planetary orbits, and will present preliminary results for representative binary star cases that illustrate our ability to constrain the planet's orbital period and inclination.


V471 Tauri's circumbinary brown dwarf non-observation Applegate, or over-restrictive assumptions? - Astronomy

4:1. The new (13) CO line map further resolves the flattened molecular gas structure first seen by Koerner et al. 1993 the size, aspect ratio, and orientation of this molecular bar are comparable to those of the optical nebula. These results strongly support an interpretation of the reflection nebulosity as an illuminated outer surface of the molecular gas disk surrounding GM Aurigae. Comparison of the observed nebula with single scattering models suggests that the disk is viewed at a latitude

30(deg) above its equator plane.

18.5, corresponding to secondary-to-primary mass ratios of

0.5. No companions were found with separations between 2'' and 31'' (

1000 AU). This null result implies a wide companion frequency below 2.3% at the 95% confidence level within the sensitivity limits of the survey. Preliminary modeling efforts indicate that we could have detected 85% of companions more massive than 0.05 Msolar and 50% above 0.03 Msolar.

2times 10(6) yrs, GM Auriga is currently the oldest T Tauri star for which a gaseous disk has been imaged. At mid-infrared wavelengths, its flux is relatively low, suggesting that clearing of dust has taken place close to the star. The clearing may be due to the aggregation of dust grains into planetesimals, a process expected to occur rapidly as accretion slows down. Our observations imply that dispersion of gas in a protoplanetary disk does not pre-date the earliest phase of planetesimal formation, supporting theories of outer planet formation which require the formation of a rock-ice core prior to gas accumulation.

4:1. The new (13) CO line map further resolves the flattened molecular gas structure first seen by Koerner et al. 1993 the size, aspect ratio, and orientation of this molecular bar are comparable to those of the optical nebula. These results strongly support an interpretation of the reflection nebulosity as an illuminated outer surface of the molecular gas disk surrounding GM Aurigae. Comparison of the observed nebula with single scattering models suggests that the disk is viewed at a latitude

30(deg) above its equator plane.

18.5, corresponding to secondary-to-primary mass ratios of

0.5. No companions were found with separations between 2'' and 31'' (

1000 AU). This null result implies a wide companion frequency below 2.3% at the 95% confidence level within the sensitivity limits of the survey. Preliminary modeling efforts indicate that we could have detected 85% of companions more massive than 0.05 Msolar and 50% above 0.03 Msolar.



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