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AAS 219 Press Conference: Extraordinary Exoplanets

posted Jan 9, 2012, 9:11 AM by Abel Mendez   [ updated Jan 11, 2012, 10:15 AM ]
Here are the abstracts of the presentations related to the AAS 219 press conference Extraordinary Exoplanets schedule on Wednesday, January 11, 2012 at 1:00 PM CST (3:00 PM AST). Some details remain subject to change. There are many presentations on exoplanets in the detection and theory sessions, others scattered in other sessions.



Presentation Number 414.07
Presentation Time: Thursday, Jan 12, 2012, 3:10 PM - 3:20 PM
Title The Kepler Search for Circumbinary Planets
Author Block William F. Welsh1, Kepler Team 
1San Diego State Univ..
Abstract We present the latest results from the Kepler search for planets in binary star systems, including transiting and non-transiting cases. In many cases, eclipse timing variations (ETVs) indicate the presence of a third body in the system. If the O-C diagram exhibits a small amplitude and short-period signal, that third body may be planetary. Kepler-16, along with several other candidate systems, will be discussed.
Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASA, Science Mission Directorate. The authors also acknowledge support from the Kepler Participating Scientists Program via NASA grant NNX08AR14G.

Presentation Number 330.02
Presentation Time: Wednesday, Jan 11, 2012, 2:10 PM - 2:20 PM
Title The Masses and Metallicities of Kepler’s Planet-hosting M Dwarfs
Author Block John A. Johnson1, S. Pineda1, M. Bottom1 
1Caltech.
Abstract While much attention is focused on Kepler’s Sun-like target stars, there are many target stars that reside at the bottom of the main sequence. Thus, Kepler provides valuable information about planet formation around the Galaxy’s most numerous denizens, the M dwarfs. We will present recent advances in understanding the fundamental physical properties of M dwarfs using both broadband photometry and optical spectroscopy. These techniques provide revised estimates of stellar masses and radii, thereby elucidating the radius distribution of planets orbiting low-mass stars. We will present the specific case studies LHS6343C and KOI-254.01, a transiting brown dwarf and hot Jupiter, respectively, orbiting two of Kepler’s least massive and most proximate target stars.

Presentation Number 404.04
Presentation Time: Thursday, Jan 12, 2012, 10:40 AM -10:50 AM
Title Planetary Construction Zones in Occultation: Eclipses by Circumsecondary and Circumplanetary Disks and a Candidate Eclipse of a Pre-Main Sequence Star in Sco-Cen
Author Block Eric E. Mamajek1, A. C. Quillen2, M. Pecaut2, F. Moolekamp2, E. L. Scott2, M. A. Kenworthy3, A. Collier Cameron4, N. Parley4 
1CTIO, University of Rochester, 2University of Rochester, 3Leiden University, Netherlands, 4University of St. Andrews, United Kingdom.
Abstract The large relative sizes of circumplanetary and circumstellar disks imply that they might be seen in eclipse in stellar light curves. We present photometric and spectroscopic data for a complex disk eclipse of a post-accretion, solar-mass pre-main sequence star. The star 1SWASP J140747.93-394542.6 is a ~16 Myr-old member of the Upper Centaurus-Lupus subgroup of Sco-Cen at 130 pc, and was discovered in a spectroscopic survey for new low-mass Sco-Cen members by Pecaut & Mamajek. SuperWASP and ASAS V-band time series photometry reveal that this star exhibited a remarkably long, deep, and complex eclipse event in April 2007. At least 5 multi-day dimming events of >0.5 mag are identified, with an asymmetric >3.3 mag deep eclipse bracketed by two pairs of ~1 mag eclipses symmetrically occurring +-12 days and +-26 days before and after. We place a firm lower limit on the period of the eclipser of 850 days. We hypothesize that this star is being eclipsed by a low-mass object with an orbiting dust disk with significant radial substructure ("rings" and gaps) and mass on the order of lunar masses. Combining theoretical predictions of the sizes and masses of circumplanetary disks around young gas giants with observational constraints on the incidence of such planets, shows that their eclipses should be of sufficient optical depth and duration to be plausibly detectable, albeit extraordinarily rarely. LSST surveys of post-accretion stars (~10 Myr) should yield disk eclipses around at least ~10-4 of the stars. Eclipses by circumplanetary and circumsecondary disks will provide us fine-scale observational constraints on the physical and chemical conditions of the dust and gas which spawn satellite systems around gas giant planets and planetary systems around stars. This research was supported by NSF grant AST-1008908 and funds from the School of Arts and Sciences at the University of Rochester.

Presentation Number 330.04
Presentation Time: Wednesday, Jan 11, 2012, 2:40 PM - 2:50 PM
Title Accurate Stellar Parameters of Low-Mass Kepler Planet Hosts
Author Block Philip Muirhead1, K. Hamren2, E. Schlawin3, B. Rojas-Ayala4, K. Covey3, J. Lloyd3 
1California Institute of Technology, 2University of California, Santa Cruz, 3Cornell University, 4American Museum of Natural History.
Abstract We report stellar parameters for low-mass planet-candidate host stars recently announced by the Kepler Mission. We obtained medium-resolution, K-band spectra of 84 low-mass Kepler Objects of Interest (KOIs). We identified one KOI as a giant; for the remaining dwarfs, we estimated effective temperatures by comparing measurements of K-band regions dominated by H2O opacity with predictions of synthetic spectra for low-mass stars. We measured overall metallicities ([M/H]) using the equivalent widths of Na I and Ca I absorption features and an empirical metallicity relation calibrated with nearby stars. With effective temperatures and metallicities, we estimate the masses and radii of the low-mass KOIs by interpolation onto two sets of evolutionary isochrones. The resultant stellar radii are significantly less than the values reported in the Kepler Input Catalogue and, by construction, correlate better with effective temperature. Using either set of isochrones, our results significantly reduce the sizes of the corresponding planet candidates, with many less than 1 Earth radius. We report recalculated equilibrium temperatures for the planet-candidates and the implications for Kepler’s yield of terrestrial exoplanets in the habitable zones of their host stars.