Kinematic for ~5200 alpha Persei candidate members

At ages exceeding 100Myr, magnetic spindown erases the initial stellar spin rate and enables rotation-based age dating (gyrochronology). The exact time at which the transition between these two regimes occurs depends on stellar mass, and has been challenging to empirically resolve due to a lack of viable calibration clusters.

The {alpha}Persei open cluster (t~80Myr, d~170pc) may provide the needed calibrator, but recent analyses of the Gaia data have provided wildly varying views of its age and spatial extent. As such, we analyze a combination of TESS, Gaia, and LAMOST data to calibrate gyrochronology at the age of {alpha}Per and to uncover the cluster's true morphology. By assembling a list of rotationally confirmed {alpha}Per members, we provide strong evidence that {alpha}Per is part of a larger complex of similarly aged stars.