Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 352, L91-L94 (1999)

Next Section Table of Contents

Letter to the Editor

Evidence for an ~80 day periodicity in the X-ray transient pulsar XTE J1946+274

Sergio Campana 1, Gianluca Israel 2 and Luigi Stella 2

1 Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate (Lc), Italy
2 Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio Catone, Roma, Italy

Received 30 August 1999 / Accepted 9 November 1999


We report evidence for an [FORMULA] d periodicity in the X-ray flux of the hard transient pulsar XTE J1946+274. The 1.3-12 keV light curve obtained with the RossiXTE All Sky Monitor shows five regularly spaced flares over a [FORMULA] year baseline starting from the outburst onset in Sept. 1998. The first and strongest flare is somewhat longer than the subsequent four flares, which recur in a fairly periodic fashion. This suggests that the profile of the first flare is dominated by the time variability of the Be star ejection episode, while the following four flares are primarily caused by the neutron star motion along an eccentric orbit.

Key words: stars: pulsars: general – stars: individual: XTE J1946+274 – X-rays: stars

Send offprint requests to: S. Campana

Correspondence to: campana@merate.mi.astro.it

SIMBAD Objects


Next Section Table of Contents

© European Southern Observatory (ESO) 1999

Online publication: December 2, 1999