IL Lup (=4U1543-47): New X-ray Outburst in June
J. M. Miller and R. A. Remillard, for the RXTE ASM Team reported the detection
of a new X-ray outburst in the black hole binary, 4U1543-47. The first
detections with the RXTE ASM indicated a flux (2-12 keV) of 0.054 (+/-
0.009) Crab on June 16.683, rapidly increasing to 0.5 Crab (June 17.122)
and 1.65 Crab (June 17.552). The X-ray spectrum was very soft, implying
that the dominant component was thermal emission from the accretion disk
(vsnet-campaign
1321, vsnet-campaign-xray
144, 145).
T. Kato noticed that the object has an orbital period of 1.123 d and
has the secondary type A2V, which are similar parameters to those of V4641
Sgr (vsnet-campaign-xray
146). Its outburst in 1992 rapidly decayed with a short time-scale
of 1.6d (vsnet-campaign-xray
148). B. Monard performed time-series observations and reported the
absence of large flares (vsnet-campaign-xray
149, 150,
151).