Related papers: TOI-880 is an Aligned, Coplanar, Multi-planet Syst…
While high stellar obliquities observed in exoplanetary systems may be attributed to processes that tilt the planetary orbits, it is also possible that they reflect misalignments between protoplanetary disks and stellar spins. This latter…
TOI-3884~b is an unusual 6.4~R$_\oplus$ planet orbiting an M4 host, whose transits display large and persistent spot-crossing events. We used the \textit{Tierras} Observatory to monitor both the long-term photometric variability of TOI-3884…
We report the measurement of the sky-projected obliquity angle $\lambda$ of the Warm Jovian exoplanet TOI-1670 c via the Rossiter-McLaughlin effect as part of the Stellar Obliquities in Long-period Exoplanet Systems (SOLES) project. We…
We report the discovery of a hot Jupiter on a 3.28-day orbit around a 1.08 M$_{Sun}$ G0 star that is the secondary component in a loose binary system. Based on follow-up radial velocity observations of TOI-858 B with CORALIE on the Swiss…
We report the observation of the transiting planet TOI-942c, a Neptunian planet orbiting a young K-type star approximately 50 Myr years old. Using Keck/HIRES, we observed a partial transit of the planet and detected an associated radial…
Despite the wide range of planet-star (mis)alignments in the mature population of transiting exoplanets, the small number of known young transiting planets are nearly all aligned with the rotation axes of their host stars, as determined by…
We present spectral observations of the multiplanet host TOI-1694 during the transit of TOI-1694b, a 26.1 $M_\oplus$ hot Neptune with a 3.77-day orbit. By analyzing radial velocities obtained from the Keck Planet Finder, we modeled the…
The mechanisms responsible for generating spin-orbit misalignments in exoplanetary systems are still not fully understood. It is unclear whether these misalignments are related to the migration of hot Jupiters or are a consequence of…
We present a catalog of stellar companions to host stars of Transiting Exoplanet Survey Satellite Objects of Interest (TOIs) identified from a marginalized likelihood ratio test that incorporates astrometric data from the Gaia Early Data…
Despite decades of effort, the mechanisms by which the spin axis of a star and the orbital axes of its planets become misaligned remain elusive. Particularly, it is of great interest whether the large spin-orbit misalignments observed are…
We report the measurement of a spectroscopic transit of TOI-1726 c, one of two planets transiting a G-type star with $V$ = 6.9 in the Ursa Major Moving Group ($\sim$400 Myr). With a precise age constraint from cluster membership, TOI-1726…
Close-in gas giants present a surprising range of stellar obliquity, the angle between a planet's orbital axis and its host star's spin axis. It is unclear whether the obliquities reflect the planets' dynamical history (e.g., aligned for in…
The angle between stellar spin axes and planetary orbits -- stellar obliquity -- probes the dynamics of planetary migration and evolution. The obliquities of giant planets have been extensively studied because they are the most easily…
We present the first results from the POSEIDON survey, aimed at constraining the dynamical origins of transiting Neptunes through stellar obliquity measurements. We report Rossiter-McLaughlin observations of two Neptunes, TOI-181 b and…
We present a test for spin-orbit alignment for the host stars of 25 candidate planetary systems detected by the {\it Kepler} spacecraft. The inclination angle of each star's rotation axis was estimated from its rotation period, rotational…
We report the discovery of TOI-2180 b, a 2.8 $M_{\rm J}$ giant planet orbiting a slightly evolved G5 host star. This planet transited only once in Cycle 2 of the primary Transiting Exoplanet Survey Satellite (TESS) mission. Citizen…
The Rossiter-McLaughlin effect allows us to measure the projected stellar obliquity of exoplanets. From the spin-orbit alignment, planet formation and migration theories can be tested to improve our understanding of the currently observed…
We measure the sky-projected stellar obliquities (\lambda) in the multiple-transiting planetary systems KOI-94 and Kepler-25, using the Rossiter-McLaughlin effect. In both cases the host stars are well-aligned with the orbital planes of the…
We report on the discovery and validation of TOI 813b (TIC 55525572 b), a transiting exoplanet identified by citizen scientists in data from NASA's Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet…
Multi-planet systems exhibit remarkable architectural diversity. However, short-period giant planets are typically isolated. Compact systems like TOI-5398, with an outer close-orbit giant and an inner small-size planet, are rare among…