The Interstellar Medium in the Kepler Search Volume

Abstract

The properties of the interstellar medium (ISM) surrounding a planetary system can impact planetary climate through a number of mechanisms, including changing the size of the astrosphere (one of the major shields for cosmic rays) as well as direct deposition of material into planetary atmospheres. In order to constrain the ambient ISM conditions for exoplanetary systems, we present observations of interstellar Na I and K I absorption towards seventeen early-type stars in the Kepler prime mission field of view. We identify 39 Na I and 8 K I velocity components, and attribute these to eleven ISM clouds. Six of these are detected towards more than one star, and for these clouds we put limits on the cloud properties, including distance and hydrogen number density. We identify one cloud with significant (>1.5 cm${}^{-3}$) hydrogen number density located within the nominal ~100 pc boundary of the Local Bubble. We identify systems with confirmed planets within the Kepler field of view that could lie within these ISM clouds, and estimate upper limits on the astrosphere sizes of these systems under the assumption that they do lie within these clouds. Under this condition, the Kepler-20, 42, and 445 multiplanet systems could have compressed astrospheres much smaller than the present-day heliosphere. Among the known habitable zone planet hosts, Kepler-186 could have an astrosphere somewhat smaller than the heliosphere, while Kepler-437 and KOI-4427 could have astrospheres much larger than the heliosphere. The thick disk star Kepler-444 may have an astrosphere just a few AU in radius.

Accepted for publication in ApJ. 19 pages, 9 figures

References in corpus (46)

• Validation of the new Hipparcos reduction
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Local Kinematics and the Local Standard of Rest
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• Kepler-16: A Transiting Circumbinary Planet
• KEPLER's First Rocky Planet: Kepler-10b
• New Mass Loss Measurements from Astrospheric Lyman-alpha Absorption
• Low cloud properties influenced by cosmic rays
• HAT-P-11b: A Super-Neptune Planet Transiting a Bright K Star in the Kepler Field
• The Structure of the Local Interstellar Medium V: Electron Densities
• An Earth-sized Planet in the Habitable Zone of a Cool Star
• Kepler-62: A five-planet system with planets of 1.4 and 1.6 Earth radii in the Habitable Zone
• Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star
• Characterizing the Cool KOIs III. KOI-961: A Small Star with Large Proper Motion and Three Small Planets
• HAT-P-7b: An Extremely Hot Massive Planet Transiting a Bright Star in the Kepler Field
• A sub-Mercury-sized exoplanet
• An ancient extrasolar system with five sub-Earth-size planets
• TrES-2: The First Transiting Planet in the Kepler Field
• Characterizing the Cool KOIs II. The M Dwarf KOI-254 and its Hot Jupiter
• Rotation Periods, Variability Properties and Ages for Kepler Exoplanet Candidate Host Stars
• Verifying asteroseismically determined parameters of Kepler stars using hipparcos parallaxes: self-consistent stellar properties and distances
• KOI-142, the King of Transit Variations, is a Pair of Planets near the 2:1 Resonance
• Kepler-63b: A Giant Planet in a Polar Orbit around a Young Sun-like Star
• The Boundary Conditions of the Heliosphere: Photoionization Models Constrained by Interstellar and In Situ Data
• Characterizing the Cool KOIs IV: Kepler-32 as a prototype for the formation of compact planetary systems throughout the Galaxy
• Validation of Twelve Small Kepler Transiting Planets in the Habitable Zone
• Kepler-21b: A 1.6REarth Planet Transiting the Bright Oscillating F Subgiant Star HD 179070
• Kepler-445, Kepler-446 and the Occurrence of Compact Multiples Orbiting Mid-M Dwarf Stars
• Kepler-20: A Sun-like Star with Three Sub-Neptune Exoplanets and Two Earth-size Candidates
• Two planets around Kapteyn's star : a cold and a temperate super-Earth orbiting the nearest halo red-dwarf
• Stellar activity mimics a habitable-zone planet around Kapteyn's star
• The Structure of the Local Interstellar Medium. III. Temperature and Turbulence
• The Structure of the Local Interstellar Medium. II. Observations of D I, C II, N I, O I, Al II, and Si II toward Stars within 100 parsecs
• Kepler-68: Three Planets, One With a Density Between That of Earth and Ice Giants
• What asteroseismology can do for exoplanets: Kepler-410A b is a Small Neptune around a bright star, in an eccentric orbit consistent with low obliquity
• Long-Period Objects in the Extrasolar Planetary Systems 47 UMa and 14 Her
• Heliospheric Response to Different Possible Interstellar Environments
• CARMA Large Area Star Formation Survey: Structure and Kinematics of Dense Gas in Serpens Main
• The Local Leo Cold Cloud and New Limits on a Local Hot Bubble
• Gas Absorption Detected from the Edge-on Debris Disk Surrounding HD32297
• The JCMT Legacy Survey of the Gould Belt: a molecular line study of the Ophiuchus molecular cloud
• Microstructure of the Local Interstellar Cloud and the Identification of the Hyades Cloud
• Detection of Potential Transit Signals in 17 Quarters of Kepler Mission Data
• Discovery of a Transiting Planet Near the Snow-Line
• Extrasolar planets and brown dwarfs around A-F type stars - VII. Theta Cygni radial velocity variations: planets or stellar phenomenon?
• Probing Our Heliospheric History I: High-Resolution Observations of Na I and Ca II Along the Solar Historical Trajectory

Cited by in corpus (4)

• Spectroscopic Evolution of Disintegrating Planetesimals: Minutes to Months Variability in the Circumstellar Gas Associated with WD 1145+017
• Strong HI Lyman-$\alpha$ variations from the 11 Gyr-old host star Kepler-444: a planetary origin ?
• The Host Stars of Keplers Habitable Exoplanets: Superflares, Rotation and Activity
• The effect of ISM absorption on stellar activity measurements and its relevance for exoplanet studies