The TESS-Keck Survey: ^* Science Goals and Target Selection

Abstract

The Kepler and TESS missions have demonstrated that planets are ubiquitous. However, the success of these missions heavily depends on ground-based radial velocity (RV) surveys, which combined with transit photometry can yield bulk densities and orbital properties. While most Kepler host stars are too faint for detailed follow-up observations, TESS is detecting planets orbiting nearby bright stars that are more amenable to RV characterization. Here, we introduce the TESS-Keck Survey (TKS), an RV program using ∼100 nights on Keck/HIRES to study exoplanets identified by TESS. The primary survey aims are investigating the link between stellar properties and the compositions of small planets; studying how the diversity of system architectures depends on dynamical configurations or planet multiplicity; identifying prime candidates for atmospheric studies with JWST; and understanding the role of stellar evolution in shaping planetary systems. We present a fully automated target selection algorithm, which yielded 103 planets in 86 systems for the final TKS sample. Most TKS hosts are inactive, solar-like, main-sequence stars (4500 K ≤ T eff <6000 K) at a wide range of metallicities. The selected TKS sample contains 71 small planets (R p ≤ 4 R ⊕), 11 systems with multiple transiting candidates, six sub-day-period planets and three planets that are in or near the habitable zone (S inc ≤ 10 S ⊕) of their host star. The target selection described here will facilitate the comparison of measured planet masses, densities, and eccentricities to predictions from planet population models. Our target selection software is publicly available and can be adapted for any survey that requires a balance of multiple science interests within a given telescope allocation.

TESS-Keck Survey. XIV. Two Giant Exoplanets from the Distant Giants Survey

“…We also required that all targets be amenable to precise RV follow up from the northern hemisphere. To impose these criteria, we began with the master target list produced by Chontos et al (2022), which contains 2136 individual TESS Objects of Interest (TOIs) among 2045 planetary systems. We then applied the following sets of filters:…”

“…Since beginning the survey in mid 2020, we have found evidence for 11 outer companions, both as resolved (i.e., complete) orbits and long-term trends. Distant Giants is part of the larger TESS-Keck Survey (TKS; Chontos et al 2022), a multiinstitutional collaboration to explore exoplanet compositions, occurrence, and system architectures (see, e.g., Dalba et al 2020;Rubenzahl et al 2021;Weiss et al 2021).…”

TOI-1136 is a Young, Coplanar, Aligned Planetary System in a Pristine Resonant Chain

“…Moreover, it provides a rare chance to obtain a stellar obliquity measurement for a young planetary system with a resonant chain of planets. We observed a total of 52 spectra of TOI-1136 with the HIRES on the 10 m Keck I telescope (Keck/HIRES; Vogt et al 1994) on the night of UTC 2022 March 11 during a transit of TOI-1136 d as part of the TESS Keck Survey (TKS; see Chontos et al 2022). We obtained the spectra with the iodine cell in the light path.…”

The Ariel Target List: The Impact of TESS and the Potential for Characterizing Multiple Planets within a System

“…Accurately knowing the planet's mass is also useful, particularly for smaller or cloudier worlds (Batalha et al 2019;Changeat et al 2020b). Several studies have explored the time needed to provide the radial velocity measurements necessary to constrain planet masses for Ariel (e.g., Barnes & Haswell 2021;Demangeon et al 2022), and the ongoing work of the radial velocity teams, both within the Ariel consortium and outside of it (e.g., Lillo-Box et al 2020;Nielsen et al 2020;Chontos et al 2021;Kaye et al 2021;Van Eylen et al 2021), is ensuring that the best targets for atmospheric characterization are followed up. Nevertheless, it may not be Figure 14.…”