Alexander Binks (IAAT) Tübingen, October 23, 2023

Rotation is at the heart of astronomy. It plays a part in the dynamics of all astronomical objects from natal molecular cloud contraction, to the pulsating signals emitted by rotating neutron stars. In this talk, I will provide a summary of the history and our current understanding of stellar rotation, particularly for Sun-like and low-mass stars during their early lifetimes. I will briefly describe photometric and spectroscopic techniques to measure stellar rotation periods, and highlight the progress of stellar rotation studies from ground-based dedicated monitoring campaigns to the colossal satellite surveys of recent years.
I will showcase how this recent deluge of data is causing a revolution in our understanding of stellar evolution and how it is being used as a useful chronometer to age-date stars and clusters. I will then describe "the TESSilator" -- my own publicly-available software which delves into the 30-min cadence TESS lightcurves and is providing rotation periods at surprisingly faint magnitudes! Finally, I will describe how the TESSilator is being used for the 4SYS project -- an ambitious campaign to spectroscopically observe ~150,000 candidate young stars in the Solar neighbourhood.