Habitable Zones & Global Climate

The 10 pc Neighborhood of Habitable Zone Exoplanetary Systems: Threat Assessment from Stellar Encounters & Supernovae

By Keith Cowing

Status Report

astro-ph.SR

October 31, 2024

Filed under astro-ph.SR, astronomy, close stellar encounters, exoplanet, Gaia DR3, habitability, Habitable Zone, HD-165155, HD-48265, Neighborhood Similarity Index, Solar Similarity Index, Stellar Cartography, Supernova, TOI-1227

The 10 pc Neighborhood of Habitable Zone Exoplanetary Systems: Threat Assessment from Stellar Encounters & Supernovae — Sky positions of exoplanet-hosting stars projected on Molleweide map. HZS are denoted by yellow-green circles, while the remaining population of exoplanets is represented by gray circles. The studied sample of 84 HZS, located within 220 pc of the Sun, is represented by crossed yellow-green circles. The three high-density HZS located near the galactic plane are labeled 1, 2 and 3 in white. The colorbar represents the stellar density, i.e., the number of stars having G ≥ 15 within a radius of 5 arcmin. — astro-ph.HE

The habitability of a planet is influenced by both its parent star and the properties of its local stellar neighborhood. Potential threats to habitability from the local stellar environment mainly arise from two factors: cataclysmic events such as powerful stellar explosions and orbital perturbations induced by close stellar encounters.

Among the 4,500+ exoplanet-hosting stars, about 140+ are known to host planets in their habitable zones. In this study, we use Gaia DR3 data to investigate the 10~pc stellar neighborhood of the 84 habitable zone systems (HZS) closest to the Sun.

We assess the possible risks that local stellar environment of these HZS pose to their habitability. In particular, we find that HD~165155 has a high stellar density around it, making it likely to experience at least one flyby encounter within a span of 5~Gyr. We also identified two high-mass stars (M≥8M⊙) as potential progenitors of supernovae, which could threaten the long-term survivability of habitable zone systems HD~48265 and TOI-1227.

Further, to quantify the similarity between habitable zone stars and the Sun, as well as their respective 10~pc stellar environments, we employ various astrophysical parameters to define a Solar Similarity Index (SSI) and a Neighborhood Similarity Index (NSI). Our analysis suggests that HD~40307 exhibits the closest resemblance to the solar system, while HD~165155 shows the least resemblance.

Tisyagupta Pyne, Ravinder K. Banyal, C. Swastik, Ayanabha De

Comments: Accepted for publication in AJ
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
Cite as: arXiv:2410.22396 [astro-ph.SR] (or arXiv:2410.22396v1 [astro-ph.SR] for this version)
https://doi.org/10.48550/arXiv.2410.22396
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Submission history
From: Ravinder Banyal
[v1] Tue, 29 Oct 2024 18:00:00 UTC (4,848 KB)
https://arxiv.org/abs/2410.22396

Astrobiology

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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