Recurrent Transient X1901+031
ATel #118; D. Galloway, R. Remillard, E. Morgan (M. I.T.), and J. Swank (NASA GSFC)
on 12 Feb 2003; 17:18 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Duncan K. Galloway (duncan@space.mit.edu)
Subjects: Optical, X-ray, Request for Observations, Binary, Neutron Star, Transient, Pulsar
Referred to by ATel #: 121
We report a new X-ray outburst in a
transient last seen in 1970-71 (Forman et al. 1976, ApJ 206, L29).
The ASM position is R.A. = 19h03m33s, Decl. = +3 12'.4 (equinox J2000.0;
estimated 3' uncertainty at 90% confidence). This position is within
the 10' error box originally estimated for X1901+031, but is almost 10' away from
the nearest ROSAT source, 1RXS J190411.9+031210. The current outburst
appears to have begun on 2003 January 31 with a flux of 40(8) mCrab
at 2-10 keV, rising to a steady flux of 130 mCrab on February 9 and 10.
Brief followup observations with the RXTE PCA instrument on February 10
show pulsations with a period of 2.763 seconds. We encourage efforts
to locate the optical counterpart, noting the likelihood of an optical
companion with an early type spectrum or Be classification.
