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ATEL # 2125; Mark Reynolds (University of Michigan), Paul Callanan (University College Cork), Takahiro Nagayama (Nagoya University)
on 11 Jul 2009; 0:29 UT
Password Certification: Mark Reynolds (email@example.com)
Subjects: Infra-Red, X-ray, Binaries, Black Holes, Transients
We obtained a series of 300s exposures in the J, H & K' bands of the field of the candidate black hole transient XTE J1652-453 (ATEL #2107) using the Sirius simultaneous 3 channel NIR imager mounted on the Infrared Survey Facility 1.4m telescope at SAAO. Within the Swift error circle (ATEL #2120), there are at least two objects visible in the K' image (see chart):
Star A: 16 52 20.4 -45 20 38.4, K' = 17.0 +/- 0.3
and the other at
Star B: 16 52 20.3 -45 20 39.9, K' = 16.9 +/- 0.3
where the positional error is 0.5''. Neither of these objects are present in either the J or H-band images.
It is not clear if either of these is the NIR counterpart, as both are below the 2MASS sensitivity limit. However, it is clear that the NIR counterpart to XTE J1652-453 in outburst must be no brighter than the limits given above.
If the absolute K' band magnitude of XTE J1652-453 is comparable to that of Sco X-1 (M_K' ~ -0.5), and if A_K' ~ 3 (N_H ~ 4e22 Atel 2120) then these measurements would suggest a conservative lower limit to the distance of approximately 5 kpc.
XTE J1652-453 K' band chart