TITLE:   GCN CIRCULAR
NUMBER:  21728
SUBJECT: GRB 170827A: ePESSTO NTT afterglow candidate
DATE:    17/08/28 02:33:35 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

J. Lyman (Univ. of Warwick), D. Homan (Univ of Edinburgh), P. D'Avanzo (INAF-OAB), Patricia Schady (MPE Garching), 
K. E. Heintz (DARK/NBI), E. Palazzi (INAF-IASFBo), L. Galbany (Univ. de Chile), J. Anderson (ESO), C. Inserra (Southampton), 
E. Kankare (QUB), K. Maguire (QUB), S. Smartt (QUB), K. W. Smith (QUB), O. Yaron (Weizmann), D. Young (QUB), 
I. Manulis (Weizmann) report:


We observed the field of GRB 170827A (Marshall et al., GCN 21718) under the extended Public ESO Spectroscopic Survey for 
Transient Objects (ePESSTO; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org ). The observations were performed on 
the ESO New Technology Telescope at La Silla with the SofI and EFOSC2 instrument in imaging mode starting from 2017-08-28 
at 00:47:05 UT (i.e. 19.58 hours from the burst). Observations were carried out with the Z, J, R and I filters.

Within the XRT error circle (Marshall et al., GCN 21718) we detect an object at the following coordinates:

RA(J2000), Dec(J2000) = 18:24:36.14, -40:12:06.3 

(+/- 0.5"). The object has a magnitude R~21.5 (based on preliminary photometry calibrated against the USNOB1 catalogue) at 
T-T0 = 20.08 hours. We cannot make any statement about variability at this time.We also notice the presence of a fainter object 
about 2.4" West.