The TESS-Keck survey. XXII. TOI-1437

Sub-Neptunes are of particular interest; due to their absence in our own solar system, we rely on demographics of exoplanets to better understand their bulk composition and formation scenarios. Here, we present the discovery and characterization of TOI-1437 b, a sub-Neptune with a 18.84 day orbit around a near-solar analog (M*=1.10+/-0.10M_{sun}_, R*=1.17+/-0.12R_{sun}_).

The planet was detected using photometric data from the Transiting Exoplanet Survey Satellite (TESS) mission and radial velocity (RV) follow-up observations were carried out as a part of the TESS-Keck Survey using both the HIRES instrument at Keck Observatory and the Levy Spectrograph on the Automated Planet Finder telescope. A combined analysis of these data reveal a planet radius of Rp=2.24+/-0.23R_{Earth}_ and a mass measurement of Mp=9.6+/-3.9M_{Earth}_).