The Rocky Worlds DDT Core Implementation Team (CIT) at STScI, together with the external Science Advisory Council (SAC), are excited to share with the science community the final targets that will form the Rocky Worlds DDT sample. These final targets are key to fulfilling the program’s objectives to look for evidence of atmospheres on rocky exoplanets orbiting M-dwarfs using 15 µm photometry with JWST/MIRI, and to study their hosts in the UV with HST to understand their high-energy environments.

The Rocky Worlds DDT Sample

There are currently four exoplanets included in the Rocky Worlds DDT: GJ 3929 b, LTT 1445 A c, LTT 1445 A b, and LHS 1140 b. After careful deliberation and study by the SAC and CIT, five more rocky exoplanets will join the sample: TOI-198 b, TOI-406 c, TOI-771 b, HD 260655 c, and TOI-244 b. The CIT is currently working to determine the number of secondary eclipse observations and how much UV coverage of the host stars are needed to reach the science goals of the program for each target. 

The CIT is also undertaking studies to understand which of these targets will require additional radial-velocity (RV) follow-up to constrain its time of secondary eclipse (via eccentricity/argument of periastron constraints) with enough precision to make efficient use of JWST observations. In particular, the SAC has recommended to start observations of TOI-198 b only when the time of secondary eclipse is known within a few hours. This will require several tens of additional RV measurements that the CIT is aiming to obtain through various facilities. Community efforts to obtain high-precision RV observations for TOI-198 b, as well as for the other targets, are very welcome. 

Virtual Information Session

In order to update the community on target selection, strategy, and other Rocky Worlds DDT matters, the CIT Leads — Néstor Espinoza and Hannah Diamond-Lowe — will be hosting a virtual information session on September 15, 2025 via WebEx from 11 a.m. to 12 p.m. (EDT). Please submit questions in advance via Slido.

Additional Updates

For additional information and updates, including the first observations and scheduling of future Rocky Worlds DDT observations, please refer to the Rocky Worlds DDT website. To contribute or reach out to the CIT, please send us an email.