[vsnet-grb-info 27424] GRB 210212A: REM early-time optical/NIR upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29527
SUBJECT: GRB 210212A: REM early-time optical/NIR upper limits
DATE:    21/02/18 10:12:02 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo at gmail.com>

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

We observed the field of GRB 210212A (Troja et al., GCN Circ. 29487) with the REM 60cm robotic 
telescope located at the ESO premise of La Silla (Chile). The observations were performed starting 
on 2021 February 12 at 04:27:01 UT (i.e. 103 seconds after the burst) at airmass 3.5 and were carried 
in the g, r, i, z, H bands simultaneously. 

>From a preliminary analysis of the first set of images, obtained at a mid time of t-t0 = 150 s, we find no 
source at the enhanced XRT position (Beardmore et al., GCN Circ. 29489) down to the following 3sigma 
magnitude upper limits: 

g > 18.2
r > 18.3
i > 17.4
z > 16.1
(AB; calibrated against the Pan-STARRS catalogue); 

H > 15.8 
(Vega; calibrated against the 2MASS catalogue).