Outburst of 4U 1608-522 Detected with RXTE/ASM
ATel #77; Robert E. Rutledge (Caltech)
on 7 Nov 2001; 18:52 UT
Distributed as an Instant Email Notice Transients
Credential Certification: R. E. Rutledge (rutledge@srl.caltech.edu)
Subjects: Optical, X-ray, Neutron Star, Transient
The
quicklook data from the RXTE/ASM indicate that the neutron star
transient low mass X-ray binary 4U 1608-522 (QX Nor) has left quiecence and
begun an X-ray outburst. Two ASM dwells on 2001 Nov 2 11:54-13:30 UT
detected the source at 7.9+/-1.5 and 4.5+/-1.9 ASM c/s (1 Crab=73 ASM
c/s). Five days later (Nov 7 10:56-10:59), it was again detected in
two consecutive dwells, with 50.3+/-2.2 c/s and 48.1+/-2.6 c/s.
This is the fourth X-ray outburst of 4U 1608-522 of the RXTE era,
including two extended outbursts in which 1608-522 remained detectable
in the daily average dwells of the ASM for a few hundred days,
following a fast-rise and decay lasting approximately 30 days. The
most recent outburst (see Mendez et al 1999 ) occurred Feb-April 1998, during which the
X-ray countrate had reached 40 ASM c/s in 4 days after the most recent
non-detection, and peaked between day 4.0-5.5. If 4U 1608-522
follows a similar lightcurve during this outburst, it will reach X-ray
peak between approximtely Nov 7 10:00 and Nov 8 22:00 UT.
