TITLE:   GCN CIRCULAR
NUMBER:  9671
SUBJECT: GRB 090715B: NOT optical observations
DATE:    09/07/16 01:42:48 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>

D. Malesani (DARK/NBI), T. Augusteijn (NOT), C. Mackay, D. King, T. 
Staley (IoA Cambridge), A. De Cia and P. Jakobsson (Univ. Iceland) 
report on behalf of a larger collaboration:

We observed the field of GRB 090715B (Vetere et al., GCN 9668) with the 
NOT equipped with StanCam, in the V, R, and I filters.

In a single 180 s exposure starting on 2009 July 16.040 UT (3.91 hr 
after the GRB), we clearly detect the object reported by Vetere et al. 
(GCN 9668) and Smith et al. (GCN 9670) with a magnitude R = 19.92 +- 
0.03 (assuming R = 17.16 for the USNO star at 16:45:24.24, +44:50:57.3). 
Although our measurement indicates only moderate fading when compared to 
the value by Smith et al. (GCN 9670), the object is missing from the 
SDSS frames of this field, and is thus very likely the afterglow of GRB 
090715B.