JWST Study Reveals Exoplanet GJ 3929b as Likely Bare Rock Without Atmosphere
By
bikenaga
9mo ago· 2 min readenInsight
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Summary
The James Webb Space Telescope's Rocky Worlds program has revealed that exoplanet GJ 3929b is likely a bare rock with no significant atmosphere. Observations using MIRI photometric imaging at 15μm showed secondary eclipse depths consistent with a dayside brightness temperature of 782±79K, matching the maximum temperature expected for a bare black rock. The findings rule out CO2-rich atmospheres thicker than 100mbar and suggest the planet has lost any secondary atmosphere. The study also identified two additional non-transiting planets in the system.
Key quotes
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These results rule out CO2-rich atmospheres thicker than 100mbar at >3sigma, suggesting that GJ 3929b has lost any significant secondary atmosphere
The radial velocity data also indicate two additional non-transiting planets in the system: a previously-identified planet in a 15.0d orbit, and a newly-identified planet candidate in a 6.1d orbit
We report first results from the JWST Rocky Worlds Director's Discretionary Time program. Two secondary eclipses of the terrestrial exoplanet GJ 3929b were recently observed using MIRI photometric imaging at 15 um. We present a reduction of these data usi
