TITLE:   GCN CIRCULAR
NUMBER:  18379
SUBJECT: GRB 151001A: NOT imaging
DATE:    15/10/02 09:07:50 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler (MPE), J. P. U. Fynbo, D. Malesani (DARK/NBI), and P. 
Jakobsson (U. Iceland) report on behalf of a larger collaboration:

We observed the field of GRB 151001A (Swift trigger 657286, Stamatikos 
et al., GCN Circ. 18373) with the 2.5-m Nordic Optical Telescope (NOT) 
equipped with ALFOSC on the evening of 01-Oct-2015 between 19:55-20:24 
UT (5 hr after the burst). In SDSS filters r and g we clearly detect the 
optical afterglow of GRB 151001A at the position given by UVOT 
(Stamatikos et al., GCN Circ. 18373). We derive AB magnitudes of

g = 22.18 +/- 0.05
r = 21.51 +/- 0.08

calibrated against SDSS field stars. The g-r color of the afterglow is 
relatively red compared to typical afterglows.