Periodic Dips from a Bright LMXB in M31

A new EXTraS paper, "Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS", has been accepted for publication on Astrophysical Journal. The paper is available on ArXiv. Starting from EXTraS results on aperiodic variability, publicly available through our archive, the brightest X-ray source in the Andromeda galaxy has revealed its true nature: periodic dips in its light curve point to a LMXB system.