The Optical Counterpart to XTE J1752-223
ATel #2263; M. A. P. Torres (CfA), P. G. Jonker (SRON/CfA), D. Steeghs (Warwick/CfA), H. Yan (CCAPP, The Ohio State U.), J. Huang, A. M. Soderberg (CfA)
on 26 Oct 2009; 12:36 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Manuel Torres (mtorres@cfa.harvard.edu)
Subjects: Optical, Request for Observations, Binary, Black Hole, Transient
We report the discovery of the optical counterpart to the new
X-ray transient and suggested black hole candidate XTE J1752-223
(ATELs #2258, #2259, #2261).
Our observations consist of three 180s i'-band images obtained
with the 6.5m Magellan Baade telescope during 2009 Oct 26 00:02-00:18
UT using IMACS. The frames were acquired with an image quality of
~1.0" and conditions were not photometric. An astrometric calibration
of the data was obtained using USNO-B1.0 objects in the field of
view. This delivered a positional rms of 0.15".
Comparison of our images with the Digitized Sky Survey, 2MASS and UKIDSS
shows a new bright point-like source at R.A (J2000)=17:52:15.09, Dec
(J2000)=-22:20:32.4 inside the 5.0" Swift/XRT position
reported by Markwardt et al. (2009, ATel #2261). The optical counterpart
is saturated in our images due to the high sky background and the
brightness of the source. A visual inspection of the field using the
USNO-B1.0 catalogue suggests that the source may be as bright as 15-16
mag in the red band.
Given the brightness of the counterpart, follow-up observations at
all wavelengths, in particular optical spectroscopy, are encouraged
while the source is still accessible from the ground.
Finding Chart
