M-Earth Archives

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Transiting Rocky Super-Earth And A Non-transiting Sub-Neptune Orbiting The M Dwarf TOI-771

by Keith CowingApril 29, 2025April 29, 2025

The origin and evolution of the sub-Neptune population is a highly debated topic in the exoplanet community.

Simulated effects of ‘bare-rock’ fresh surface albedo profiles from Hu et al. (2012a), varying regolith grain sizes of basalt, and npFe0 /graphite space weathering on simulated emission observations in the MIRI LRS bandpass (5 − 12 µm). Brightness temperature ratios in the MIRI F1500W and Spitzer IRAC2 bandpasses show similar trends. Planets too hot for solid surfaces (Tirr ≳ 1250 K) are not shown. Results are dependent on the exact stellar properties, and we include results for a GJ 367-like M1 star and a TRAPPIST-1-like M7.5 star as bounding cases defining the width of each colored band. This roughly encompasses the spread expected for M-Earths. A trend of increasing brightness temperature ratio (R) with irradiation temperature (Tirr) can be explained by grain sizes increasing with temperature or stronger space weathering on closer-in planets, as explored in §3.2. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Population-level Hypothesis Testing with Rocky Planet Emission Data: A Tentative Trend in the Brightness Temperatures of M-Earths

by Keith CowingDecember 10, 2024

Determining which rocky exoplanets have atmospheres, and why, is a key goal for JWST. So far, emission observations of individual rocky exoplanets orbiting M stars (M-Earths) have not provided definitive […]

M-Earth

A Transiting Rocky Super-Earth And A Non-transiting Sub-Neptune Orbiting The M Dwarf TOI-771

Population-level Hypothesis Testing with Rocky Planet Emission Data: A Tentative Trend in the Brightness Temperatures of M-Earths

The Role Of Minerals In Prebiotic Evolution: Implications For Identifying Worlds With The Potential For Life’s Origin

Gen-EBM: An Energy Balance Model For Terrestrial Planets. Climate Multistability From Snowball To Post-runaway Greenhouse Climates

Astrometric Planet Search Around Southern Ultracool Dwarfs: V. Discovery Of The Exoplanet Candidate PALTA-1 b

Hubble Space Telescope Observations of Active Asteroid (101955) Bennu

SOPHIE And TESS Characterization Of Fourteen TESS Objects Of Interest: Nine Planetary Systems And Five Low-mass Stellar Companions