Observations of Accretion Disc-regulated Stellar Angular Momentum Evolution in Fully Convective Pre-main Sequence Stars

We re-address the theory of accretion disc-regulated angular momentum evolution for fully convective pre-main sequence stars in the Orion Nebula Cluster (ONC) and Taurus-Auriga. We gathered rotation periods from the literature, checking for previously identified source of bias, and re-calculated stellar radii in a consistent manner using recently updated spectral type estimations and newly established intrinsic colours, effective temperatures, and bolometric corrections for fully convective pre-main sequence stars. We find that disc-hosting stars (Class IIs) contain less specific stellar angular momentum than the disc-less stars (Class IIIs) which we interpret as indicating accretion disc-regulated stellar angular momentum evolution whereby the efficiency of this process is dependent on the lifetime of the accretion disc.