The JWST Rocky Worlds DDT Program reveals GJ 3929B to likely be a bare rock
16 hours ago
- #exoplanet
- #JWST
- #astrophysics
- First results from the JWST Rocky Worlds DDT program reveal GJ 3929b as likely a bare rock.
- Two secondary eclipses of GJ 3929b observed with MIRI photometric imaging at 15 µm.
- Updated SPARTA pipeline used for data reduction; refined planet mass, radius, and eclipse timing with TESS and MAROON-X data.
- Secondary eclipse depths of 177+47-45 ppm and 143+34-35 ppm recovered, consistent with a nearly circular orbit.
- Dayside brightness temperature of GJ 3929b is 782±79 K, aligning with a bare, black rock scenario.
- Results rule out CO2-rich atmospheres thicker than 100 mbar, suggesting loss of any significant secondary atmosphere.
- Radial velocity data indicate two additional non-transiting planets in the system: one at 15.0d orbit and a new candidate at 6.1d orbit.