Theia 456; a stellar stream in the Milky Way disk

In particular, several stellar streams have been recently discovered that are comprised of hundreds to thousands of stars and span several hundred parsecs. We analyze one such structure, Theia 456, a low-density stellar stream extending nearly 200pc and 20{deg} across the sky.

By supplementing Gaia astrometric data with spectroscopic metallicities from Large Sky Area Multi-Object Fiber Spectroscopic Telescope and photometric rotation periods from the Zwicky Transient Facility and the Transiting Exoplanet Survey Satellite, we establish Theia 456's radial velocity coherence, and we find strong evidence that members of Theia 456 have a common age (~175Myr), common dynamical origin, and formed from chemically homogeneous prestellar material ([Fe/H]=-0.07dex).