894 research outputs found
The NASA Exoplanet Archive: Data and Tools for Exoplanet Research
We describe the contents and functionality of the NASA Exoplanet Archive, a
database and tool set funded by NASA to support astronomers in the exoplanet
community. The current content of the database includes interactive tables
containing properties of all published exoplanets, Kepler planet candidates,
threshold-crossing events, data validation reports and target stellar
parameters, light curves from the Kepler and CoRoT missions and from several
ground-based surveys, and spectra and radial velocity measurements from the
literature. Tools provided to work with these data include a transit ephemeris
predictor, both for single planets and for observing locations, light curve
viewing and normalization utilities, and a periodogram and phased light curve
service. The archive can be accessed at
http://exoplanetarchive.ipac.caltech.edu.Comment: Accepted for publication in the Publications of the Astronomical
Society of the Pacific, 4 figure
Radial Velocity Prospects Current and Future: A White Paper Report prepared by the Study Analysis Group 8 for the Exoplanet Program Analysis Group (ExoPAG)
[Abridged] The Study Analysis Group 8 of the NASA Exoplanet Analysis Group
was convened to assess the current capabilities and the future potential of the
precise radial velocity (PRV) method to advance the NASA goal to "search for
planetary bodies and Earth-like planets in orbit around other stars.: (U.S.
National Space Policy, June 28, 2010). PRVs complement other exoplanet
detection methods, for example offering a direct path to obtaining the bulk
density and thus the structure and composition of transiting exoplanets. Our
analysis builds upon previous community input, including the ExoPlanet
Community Report chapter on radial velocities in 2008, the 2010 Decadal Survey
of Astronomy, the Penn State Precise Radial Velocities Workshop response to the
Decadal Survey in 2010, and the NSF Portfolio Review in 2012. The
radial-velocity detection of exoplanets is strongly endorsed by both the Astro
2010 Decadal Survey "New Worlds, New Horizons" and the NSF Portfolio Review,
and the community has recommended robust investment in PRVs. The demands on
telescope time for the above mission support, especially for systems of small
planets, will exceed the number of nights available using instruments now in
operation by a factor of at least several for TESS alone. Pushing down towards
true Earth twins will require more photons (i.e. larger telescopes), more
stable spectrographs than are currently available, better calibration, and
better correction for stellar jitter. We outline four hypothetical situations
for PRV work necessary to meet NASA mission exoplanet science objectives.Comment: ExoPAG SAG 8 final report, 112 pages, fixed author name onl
Model-Independent Stellar and Planetary Masses from Multi-Transiting Exoplanetary Systems
Precise exoplanet characterization requires precise classification of
exoplanet host stars. The masses of host stars are commonly estimated by
comparing their spectra to those predicted by stellar evolution models.
However, spectroscopically determined properties are difficult to measure
accurately for stars that are substantially different from the Sun, such as
M-dwarfs and evolved stars. Here, we propose a new method to dynamically
measure the masses of transiting planets near mean-motion resonances and their
host stars by combining observations of transit timing variations with radial
velocity measurements. We derive expressions to analytically determine the mass
of each member of the system and demonstrate the technique on the Kepler-18
system. We compare these analytic results to numerical simulations and find the
two are consistent. We identify eight systems for which our technique could be
applied if follow-up radial velocity measurements are collected. We conclude
this analysis would be optimal for systems discovered by next generation
missions similar to TESS or PLATO, which will target bright stars that are
amenable to efficient RV follow-up.Comment: 9 pages, 1 figure, submitted to Ap
Exoplanet atmospheres with GIANO II. Detection of molecular absorption in the dayside spectrum of HD 102195b
The study of exoplanetary atmospheres is key to understand the differences
between their physical, chemical and dynamical processes. Up to now, the bulk
of atmospheric characterization analysis has been conducted on transiting
planets. On some sufficiently bright targets, high-resolution spectroscopy
(HRS) has also been successfully tested for non-transiting planets. We study
the dayside of the non-transiting planet HD 102195b using the GIANO
spectrograph mounted at TNG, demonstrating the feasibility of atmospheric
characterization measurements and molecular detection for non-transiting
planets with the HRS technique using 4-m class telescopes. The Doppler-shifted
planetary signal changes on the order of many km/s during the observations, in
contrast with the telluric absorption which is stationary in wavelength,
allowing us to remove the contamination from telluric lines while preserving
the features of the planetary spectrum. The emission signal from HD 102195b's
atmosphere is then extracted by cross-correlating the residual spectra with
atmospheric models. We detect molecular absorption from water vapor at
4.4 level. We also find convincing evidence for the presence of
methane, which is detected at the 4.1 level. The two molecules are
detected with a combined significance of 5.3, at a semi-amplitude of
the planet radial velocity km/s. We estimate a planet true mass
of and orbital inclination between 72.5 and
84.79 (1). Our analysis indicates a non-inverted atmosphere
for HD 102195b, as expected given the relatively low temperature of the planet,
inefficient to keep TiO/VO in gas phase. Moreover, a comparison with
theoretical expectations and chemical model predictions corroborates our
methane detection and suggests that the detected and signatures
could be consistent with a low C/O ratio.Comment: 12 pages, 12 figures, accepted for publication in A&
Astrometry and Exoplanets: the Gaia Era, and Beyond
The wealth of information in the Gaia catalogue of exoplanets will constitute
a fundamental contribution to several hot topics of the astrophysics of
planetary systems. I briefly review the potential impact of Gaia micro-arsec
astrometry in several areas of exoplanet science, discuss what key follow-up
observations might be required as a complement to Gaia data, and shed some
light on the role of next generation astrometric facilities in the arena of
planetary systems.Comment: 6 pages, 1 figure. Proceedings of the final ELSA Conference 'Gaia: at
the frontiers of astrometry', Sevres (France), 7-11 June 2010. To appear in
EAS Publication Series, EDP Science
- …