Detectability of Earth-like Planets in Circumstellar Habitable Zones of Binary Star Systems with Sun-like Components

Abstract

Given the considerable percentage of stars that are members of binaries or stellar multiples in the Solar neighborhood, it is expected that many of these binaries host planets, possibly even habitable ones. The discovery of a terrestrial planet in the alpha Centauri system supports this notion. Due to the potentially strong gravitational interaction that an Earth-like planet may experience in such systems, classical approaches to determining habitable zones, especially in close S-Type binary systems, can be rather inaccurate. Recent progress in this field, however, allows to identify regions around the star permitting permanent habitability. While the discovery of alpha Cen Bb has shown that terrestrial planets can be detected in solar-type binary stars using current observational facilities, it remains to be shown whether this is also the case for Earth analogues in habitable zones. We provide analytical expressions for the maximum and RMS values of radial velocity and astrometric signals, as well as transit probabilities of terrestrial planets in such systems, showing that the dynamical interaction of the second star with the planet may indeed facilitate the planets detection. As an example, we discuss the detectability of additional Earth-like planets in the averaged, extended, and permanent habitable zones around both stars of the alpha Centauri system.

accepted for publication in The Astrophysical Journal

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Cited by in corpus (13)

• Calculating the Habitable Zone of Binary Star Systems I: S-Type Binaries
• The Center of Light: Spectroastrometric Detection of Exomoons
• Constraining the Radiation and Plasma Environment of the Kepler Circumbinary Habitable Zone Planets
• Dynamics and habitability in circumstellar planetary systems of known binary stars
• Quantifying the Influence of Jupiter on the Earth's Orbital Cycles
• S-Type and P-Type Habitability in Stellar Binary Systems: A Comprehensive Approach III. Results for Mars, Earth, and super-Earth Planets
• Can there be additional rocky planets in the Habitable Zone of tight binary stars with a known gas giant?
• The Habitable Zone of Kepler-16: Impact of Binarity and Climate Models
• Effects of Proxima Centauri on Planet Formation in Alpha Centauri
• Dynamics and habitability of the TESS circumbinary systems TOI-1338 and TIC-172900988
• Can Planets Exist in the Habitable Zone of 55~Cancri?
• Simulations of Triple Microlensing Events I: Detectability of a scaled Sun-Jupiter-Saturn System
• Dynamics and Habitability in Binary Star Systems