Outburst from 4U 0115+63 in progress
ATel #40; Wilson, R. B. & B. A. Harmon, NASA/MSFC; M. H. Finger, USRA
on 1 Mar 1999; 21:59 UT
Credential Certification: Robert B. Wilson (robert.b.wilson@msfc.nasa.gov)
Subjects: X-ray, Gamma Ray, Binary, Transient, Pulsar
An outburst is currently being detected from the Be/x-ray pulsar
4U 0115+63. Pulsations from the source were first detected on
Feb 22, 1999, at a frequency of 0.27666170(75) Hz, assuming the
binary orbit ephemeris in Bildsten, et al.,1997, Ap J. Suppl.
113,367. The RMS average pulsed flux in the 20-50 keV energy range
on Feb 22 and Feb 23 were (0.132 +/- 0.030) keV cmE-2 sE-1 and
(0.177 +/- 0.024) keV cmE-2 sE-1, respectively. The source is
detected by Earth occultation after Feb 18, reaching an average
intensity between Feb 20 and Feb 23 of (0.31 +/-0.08) keV cmE-2
sE-1 in the 20-50 keV band. The RMS average pulsed flux rose to
(0.466 +/-0.026) keV cmE-2 sE-1 on Feb 27.
