Brown Dwarf Atmospheres As The Potentially Most Detectable And Abundant Sites For Life

We show that the total habitable volume in the atmospheres of cool brown dwarfs with effective temperatures of ∼250-350 K is possibly larger by two orders of magnitude than that of Earth-like planets.

We also study the role of aerosols, nutrients and photosynthesis in facilitating life in brown dwarf atmospheres. Our predictions might be testable through searches for spectral edges in the near-infrared and chemical disequilibrium in the atmospheres of nearby brown dwarfs that are either free-floating or within ∼10 AU of stars.

For the latter category, we find that the James Webb Space Telescope (JWST) may be able to achieve a signal-to-noise ratio of ∼5 after a few hours integration per source for the detection of biogenic spectral features in ∼103 cool brown dwarfs.

Manasvi Lingam, Abraham Loeb
(Submitted on 27 May 2019)
Comments: 17 pages; 3 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:1905.11410 [astro-ph.EP] (or arXiv:1905.11410v1 [astro-ph.EP] for this version)
Submission history
From: Manasvi Lingam
[v1] Mon, 27 May 2019 18:00:02 UTC (229 KB)
https://arxiv.org/abs/1905.11410
Astrobiology