NuSTAR Discovery of an Unusually Steady Long-term Spin-up of the Be Binary 2RXP J130159.6-635806
Roman A. Krivonos et al. 2015 ApJ 809 140
Observations of X-ray pulsar 2RXP J130159.6–635806 suggest it has undergone strong and steady spin-up for the last 20 years, likely as a result of long-term mass accretion.