Discovery of the optical counterpart to XTEJ1748-361=A1744-36
ATel #267; D. Steeghs (CfA), M. A.P. Torres (CfA), J. E.McClintock (CfA), M. R.Garcia (CfA), G. Mallen-Ornelas (CfA)
on 9 Apr 2004; 22:24 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Manuel Torres (mtorres@cfa.harvard.edu)
Subjects: Radio, Infra-Red, Optical, X-ray, Request for Observations, Binary, Black Hole, Neutron Star, Transient
We report the discovery of the optical counterpart to the X-ray
transient XTE J1748-361 using the 6.5m Magellan-Clay telescope at Las
Campanas Observatory. Several 5-minute images in the V and R bands
were obtained using the MagIC camera on May 31 as well as November 9 2003
when the object was reported in outburst (ATEL #204). Seeing conditions
were 0.8-1.0 arcsec across a field of view of 2.4'x2.4' at 0.069 arcsec/pixel.
The images reveal an optical counterpart that is detected in the V and
R band on November 9 that is not present in the May 'quiescent' frames.
This counterpart corresponds to one of the faint X-ray sources
reported by Torres et al. (ATEL #238) at a position of
17:48:13.13 -36:07:58.17 J2000 and is within the 40 arcsec Ariel error circle of
A1744-36. Furthermore, Rupen et al. (ATEL #210) detected a radio source at this
position with the VLA during the November 2003 outburst.
We therefore conclude that the X-ray transient XTEJ1748-361 (ATEL
#204, #265, #266) and the Ariel source A1744-36 are indeed the same
and that we have detected its optical counterpart.
We encourage further observations given its current activity now that
its position has been established.
A finderchart comparing the two Magellan epochs is available at: http://hea-www.harvard.edu/~dsteeghs/Images/A1744_ID.jpg
Finder chart for A1744-36
