Rapid rotation in red giant stars is the direct result of binary interaction. We present a catalog of 3217 active giant candidates in APOGEE DR16 that we identify by their anomalous spectroscopic properties returned by ASPCAP, the APOGEE stellar parameters pipeline. We confirm 1631 as rapid rotators with v sini measurements. We also see a significant population of intermediate rotators, which could represent post-merger stars. The binary fraction among the rapid rotators is 86%. We find that the fraction of single rapidly rotating red giants is anti-correlated with metallicity and discuss future prospects for large survey samples of interacting binary stars.

Poster 18