TITLE:   GCN CIRCULAR
NUMBER:  32145
SUBJECT: GRB 220527A: REM optical/NIR observations
DATE:    22/05/28 15:04:15 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

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

We observed the field of GRB 220527A (Ursi et al., GCN Circ. 32129; Fermi GBM Team, GCN Circ. 32130; Bissaldi et al., GCN Circ. 32131) with the REM 60cm robotic telescope  located at the ESO premise of La Silla (Chile). The observations were carried in the g, r, i, z, J and K bands, starting on 2022 May 28 at 07:27:54 UT (i.e. about 22.2 hours after the burst). 

From preliminary photometry we derive the following magnitudes and upper limits (3sigma c.l.) for the optical afterglow (Tohuvavohu et al., GCN Circ. 32136; Imai et al., GCN Circ. 32138; Xu et al., GCN 32141; de Wet et al., GCN Circ. 32143):


g = 20.4 +/- 0.3 (*)
r = 19.4 +/- 0.2
i = 19.4 +/- 0.2
z > 18.4
(* marginal detection; AB calibrated against the Pan-STARRS catalogue)

J > 17.7
K > 14.9
(Vega; calibrated against the 2MASS catalogue) 


at a mid time of t-t0 ~ 22.4 hours.