The TESS-Keck Survey. XVI. Mass Measurements for 12 Planets in Eight Systems

TL;DR

This paper reports precise mass measurements for 12 exoplanets in eight systems, aiding future atmospheric studies with JWST by providing detailed planetary parameters and insights into their compositions.

Contribution

It presents new mass measurements for 11 planets and confirms a super-Jovian planet, using a homogeneous modeling approach to support atmospheric characterization efforts.

Findings

Mass measurements for 11 planets in 8 systems.

Discovery and confirmation of a temperate super-Jovian planet.

Analysis of planetary compositions and atmospheric prospects.

Abstract

With JWST's successful deployment and unexpectedly high fuel reserves, measuring the masses of sub-Neptunes transiting bright, nearby stars will soon become the bottleneck for characterizing the atmospheres of small exoplanets via transmission spectroscopy. Using a carefully curated target list and more than two years' worth of APF-Levy and Keck-HIRES Doppler monitoring, the TESS-Keck Survey is working toward alleviating this pressure. Here we present mass measurements for 11 transiting planets in eight systems that are particularly suited to atmospheric follow-up with JWST. We also report the discovery and confirmation of a temperate super-Jovian-mass planet on a moderately eccentric orbit. The sample of eight host stars, which includes one subgiant, spans early-K to late-F spectral types ($T_\mathrm{eff} =$ 5200--6200 K). We homogeneously derive planet parameters using a joint photometry and radial velocity modeling framework, discuss the planets' possible bulk compositions, and comment on their prospects for atmospheric characterization.