Characterizing small, warm exoplanets via precise radial velocity mass measurements

Exoplanet transit surveys are rapidly expanding the sample of known small (<4 REarth) exoplanets. Although transit observations allow us to measure these planets’ radii and even probe their atmospheres, precise mass measurements are necessary to constrain these planets’ bulk densities and compositions, as well as interpret atmospheric observations. In my talk, I will share my work measuring the masses of two small exoplanets. The first is HD79211 b (GJ 338 b), a sub-Neptune-sized planet on a 24.4 day orbit around one member of an M0 binary. Using observations from HARPS-N, we validate this planet candidate, which was originally discovered using CARMENES RVs (González-Álvarez et al. 2020). The second is an Earth-sized TESS candidate and target of JWST atmospheric observations, which has public HARPS RV measurements, but no published mass measurement. In an ongoing effort, I am working to model the host star’s magnetic cycle and stellar activity in an effort to constrain the mass of this candidate.