Astronomers Release Catalog of Rotation Periods for Over One Million Stars

A collaborative team of astronomers has released a comprehensive catalog containing rotation periods for more than one million stars, marking one of the largest compilations of stellar spin rates to date. The dataset, derived primarily from photometric observations collected by the Transiting Exoplanet Survey Satellite (TESS) and supplemented with archival Kepler measurements, provides rotation periods ranging from a few hours to several months across a broad spectrum of stellar types and ages. By applying automated period‑finding algorithms and rigorous validation procedures, the researchers identified periodic brightness modulations caused by starspots, enabling precise determination of rotation rates for stars previously lacking such information.

The new catalog is expected to enhance studies of stellar magnetic activity, angular momentum evolution, and gyrochronology, offering a valuable benchmark for models that link rotation to stellar age. The authors have made the full dataset publicly available through an online repository, encouraging its integration into ongoing surveys and theoretical work. Early analyses already suggest refinements to age‑rotation relations for low‑mass stars and reveal patterns of differential rotation in certain stellar populations. The release has attracted attention within the astrophysics community, as reflected in discussion threads on platforms such as Hacker News, where the announcement garnered notable interest and brief commentary.