Characterizing Exoplanets for Assessing Their Potential Habitability

Abstract

The Statistical-likelihood Exoplanetary Habitability Index (SEPHI) serves as a valuable tool for prioritizing targets for further study and identifying potentially habitable environments. In this paper, we present SEPHI 2.0, which incorporates several key improvements: (1) updated methods for estimating exoplanet internal structures and magnetic fields; (2) the inclusion of orbital eccentricity in assessing the potential for liquid water on an exoplanet's surface; and (3) a new exoplanet mass-radius relationship. SEPHI 2.0 retains its probabilistic framework and combines the different subindexes by selecting the most restrictive one. In SEPHI 2.0, atmospheric retention is consolidated into a single index that incorporates both thermal (Jeans escape) and nonthermal (stellar wind and magnetic effect) processes. Recent advancements in estimating exoplanet internal structures and magnetic fields have been integrated. Additionally, a new empirical exoplanet mass-radius relationship is introduced. All this is incorporated into the SADE code, which uses key data on exoplanets and their host stars to assess habitability and prioritize targets for further study, providing a comprehensive output of an exoplanetary system's physical characteristics. SADE is available as a free online tool. Notably, this is the first approach to including estimated exoplanet magnetic 8elds in a habitability index. The SADE software facilitates the identification of potentially habitable exoplanets. Among the 5500+ confirmed exoplanets, only a few-such as Kepler-62f and GJ 514b achieve SEPHI 2.0 scores close to 1. It is also noticeable that, according to our studies, TRAPPIST-1 f and g are ranked higher than TRAPPIST-1 e in terms of habitability potential.

13 pages, 3 figures

References in corpus (44)

• Habitable Zones Around Main-Sequence Stars: New Estimates
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits
• The stellar activity-rotation relationship and the evolution of stellar dynamos
• Ages for illustrative field stars using gyrochronology: viability, limitations and errors
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Growth Model Interpretation of Planet Size Distribution
• The Geneva-Copenhagen Survey of the Solar neighbourhood III. Improved distances, ages, and kinematics
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Rotation and differential rotation of active Kepler stars
• Rotation periods of 12 000 main-sequence Kepler stars: Dependence on stellar spectral type and comparison with v sin i observations
• The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars
• Oxygen Abundances in Nearby FGK Stars and the Galactic Chemical Evolution of the Local Disk and Halo
• A Detailed Model Grid for Solid Planets from 0.1 through 100 Earth Masses
• The inner edge of the habitable zone for synchronously rotating planets around low-mass stars using general circulation models
• Inferring probabilistic stellar rotation periods using Gaussian processes
• The Solar Neighborhood XXXVII: The Mass-Luminosity Relation for Main Sequence M Dwarfs
• Habitable Moist Atmospheres On Terrestrial Planets Near the Inner Edge Of the Habitable Zone Around M-dwarfs
• A uniform asteroseismic analysis of 22 solar-type stars observed by Kepler
• XHIP: An Extended Hipparcos Compilation
• Gaia DR2 study of Herbig Ae/Be stars
• Effects of M dwarf magnetic fields on potentially habitable planets
• Rotation Periods, Variability Properties and Ages for Kepler Exoplanet Candidate Host Stars
• Identifying the young low-mass stars within 25 pc. II. Distances, kinematics and group membership
• Main-Sequence Effective Temperatures from a Revised Mass-Luminosity Relation Based on Accurate Properties
• The WIRED Survey II: Infrared Excesses in the SDSS DR7 White Dwarf Catalog
• The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9m Program: Trigonometric Parallaxes of Nearby Low-Mass Active and Young Systems
• New rotation period measurements for M dwarfs in the southern hemisphere: an abundance of slowly rotating, fully convective stars
• CARMENES input catalogue of M dwarfs IV. New rotation periods from photometric time series
• Age Gradients in the Stellar Populations of Massive Star Forming Regions Based on a New Stellar Chronometer
• Rotation periods and ages of solar analogs and solar twins revealed by the Kepler Mission
• Rotation in the Pleiades with K2: II. Multi-Period Stars
• On the protection of extrasolar Earth-like planets around K/M stars against galactic cosmic rays
• Erosion of an exoplanetary atmosphere caused by stellar winds
• Star Formation and Young Population of the HII Complex Sh2-294
• Early Mars' habitability and global cooling by H2-based methanogens
• Activity of TRAPPIST-1 analogue stars observed with TESS
• New rotation period measurements of 67,163 Kepler stars
• A primordial atmospheric origin of hydrospheric deuterium enrichment on Mars
• Statistical-likelihood Exo-Planetary Habitability Index (SEPHI)
• The Gaia-ESO Survey: Spectroscopic-asteroseismic analysis of K2 stars in Gaia-ESO
• Internal Structure and Magnetic Moment of Rocky Planets. Application to the first exoplanets discovered by TESS