X0331+53
Abstract
F. Makino and the Ginga Team, Institute of Space and Astronautical Science, telex: "The All Sky Monitor onboard Ginga discovered the recurrent x-ray transient pulsar X0331+53 (= V0332+53 = BQ Cam) in a bright x-ray outburst. The 1- to 20-keV x-ray intensity was < 70, about 170, about 250, and about 240 mCrab on Sept. 15.77, 18.68, 19.68, and 20.68 UT, respectively. This is a third outburst of this source known to date, following the ones in 1973 (Whitlock 1989, Ap.J. 344, 371) and 1983-1984 (IAUC 3891). Pointed observations with the Large Area Proportional Counter onboard Ginga made on Sept. 19.91, 20.24, and 20.83, each for about 30 min, yielded the preliminary heliocentric pulsation period of 4.3767 +/- 0.0003 s; the source exhibits very hard x-ray spectra and rapid x-ray flickering. These properties are consistent with those observed previously."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- September 1989
- Bibcode:
- 1989IAUC.4858....1M