GCN Circular 23323

P. D'Avanzo, S.Covino, D. Fugazza, A. Melandri (INAF-OAB), on behalf of the REM team, report:

We observed the optical counterpart of GRB 181010A (Melandri et al. GCN 23309
Not found
 
 
; Gorbovskoy et al. GCN 23310
Not found
 
 
; Martone et al. GCN 23311
Not found
 
 
; 
Troja et al. GCN 23312
Not found
 
 
; Vielfaure et al. GCN 23315
Not found
 
 
; Emery et al. GCN 23317
Not found
 
 
; D'Avanzo et al. GCN 23319
Not found
 
 
) with the REM 60cm robotic telescope 
located at the ESO premise of La Silla (Chile). The observations were performed starting on 2018 October 10 at 05:56:52 UT (i.e. 61 seconds 
after the burst) and were carried simultaneously in the g, r, i, z, and H bands. 

The GRB afterglow is detected in the first set of optical and NIR images. From preliminary photometry we estimate the following magnitudes:

r = 18.2 +/- 0.2 (AB; calibrated against the Pan-STARRS catalogue)
H = 14.4 +/- 0.2 (Vega; calibrated against the 2MASS catalogue) 

at a mean time of 4.1 minutes from the GRB time (Melandri et al. GCN 23309
Not found
 
 
).