1989 outburst from A1744-361
ATel #268; Jean in 't Zand (SRON)
on 11 Apr 2004; 13:22 UT
Credential Certification: Jean in' t Zand (jeanz@sron.nl)
Subjects: X-ray, A Comment, Neutron Star, Transient
We note that, apart from the outburst in 1976, leading to its
discovery (Carpenter et al 1977, MNRAS 179, 27P), and the recent
outbursts in December 2003 and April 2004 (Remillard et al. 2003, ATel
204; Markwardt & Swank 2004, ATel 265), A1744-361 was also detected on
August 22-23, 1989, with COMIS-TTM (In 't Zand 1992, PhD thesis, see http://wfc.sron.nl/~jeanz/thesis.ps.gz ). The flux was 60 mCrab (2-30
keV), while it was undetectable 5 months earlier and 1 month later at
detection thresholds of about 6 mCrab. The spectrum was consistent
with thermal bremsstrahlung of temperature 7.2 +/- 1.2 keV and NH<1E22
cm-2. Emelyanov et al. (2001; Astron. Lett. 27, 908) reported the
detection of an X-ray burst from this source from the same data.
COMIS-TTM was a coded aperture camera on the Mir space station,
quite similar to BeppoSAX-WFC but with an angular resolution of 2 arcmin.
