1998A&A...335..587H

RXTE observations of the Be/X-ray binary pulsar RX J0146.9+6121 in July 1997 revealed the begin of a new X-ray outburst, the second observed after its discovery in August 1984 by EXOSAT. The flux increased by nearly a factor of five within one week reaching 3.2x10^–10erg/cm²/s. The corresponding X-ray luminosity for a distance of 2.5kpc is an order of magnitude brighter than the level observed between 1994 and 1996 by ASCA and ROSAT. The neutron star spin period was measured to 1404.2±1.2s indicating the start of a spin-up phase as expected for increased matter accretion onto the neutron star during outburst. A combined spectral analysis of ASCA and RXTE data revealed an exponential cutoff in the power-law spectrum at 4keV.