GCN Circular 22162
Subject
GRB 171123A: Tautenburg observations
Date
2017-11-24T16:01:55Z (6 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
S. Schmidl, B. Stecklum, S. Klose, A. Nicuesa Guelbenzu, and C. Hoegner
(Thueringer Landessternwarte Tautenburg) report:
We observed the field of GRB 171123A (Evans et al., GCN 22148) in the Rc
band using the Tautenburg Schmidt telescope equipped with the prime focus
CCD camera. Observations started at 04:01 UT, about 14 hr after the burst.
At the SE border of the enhanced XRT error circle (radius 1.9 arcsec; Goad
et al., GCN 22150; 1.5 arcsec acc. to the newest results presented at
http://www.swift.ac.uk/xrt_positions/00791922/) we find a faint source at
coordinates
RA (J2000) : 12:24:59.29,
Dec (J2000): 32:30:03.4 (+/- 0.6 arcsec).
At a midtime of 04:46 UT we measure a preliminary magnitude of Rc (Vega) =
22.7 +/- 0.3, calibrated against SDSS field stars.
The non-detection of this source by RATIR eight hours after our observing
run (Butler et al., GCN 22160) suggests that this was the GRB afterglow.
We caution however that this is only a 3-sigma detection.