Abstract

Contributed Talk - Splinter JungeAG

Tuesday, 16 September 2025, 15:30

Determining Rotation Periods for Stellar Targets Under Consideration within the JWST Rocky Worlds Program

Meng Ho Tan (1), Stefan Dreizler (1), Eric Gaidos (2)
(1) Institute for Astrophysics and Geophysics, Georg August University of Göttingen; (2) Department of Earth Sciences, University of Hawai’i at Mānoa

The James Webb Space Telescope (JWST) Rocky Worlds Program has been established to explore nearby rocky exoplanets, with the aim of revealing the presence of atmosphere and the types of atmospheric composition. Nearby M-dwarf systems are identified for this survey for their accessibility in transiting exoplanet studies and JWST secondary eclipse follow-up. A list of exoplanets have been shortlisted as the Targets Under Consideration (TUC) and 500 hours of JWST time has been allocated to survey some of these. Escape of planetary atmospheres can be driven by extreme ultraviolet and X-ray (XUV) radiation, and that the radiation level is in turn governed by the rotation of the star via its magneto dynamo, it is thus insightful to assess the stellar rotation systematically. Since age reveals the extent of atmospheric loss that a planet has experienced, it is also instructive to deduce the stellar age via gyrochronology (a rotation-age relation). Driven by these incentives, this work attempts to independently confirm the published rotation periods of TUC stars and identify new rotation signals. Spectroscopic indicator time series from CARMENES and HARPS are employed to detect the rotation periods with GLS periodogram and Gaussian process methods. About 50% of the literature rotation periods have been confirmed so far.