[vsnet-grb-info 9403] GRB 100418A: late time optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10883
SUBJECT: GRB 100418A: late time optical observations
DATE:    10/06/25 16:45:00 GMT
FROM:    Vasilij Rumjantsev at CrAO  <rum at crao.crimea.ua>

V. Rumyantsev (CrAO), A. Pozanenko (IKI)  report on behalf of  larger GRB
follow-up collaboration:

We observed the field of the Swift GRB 100418A (Marshall et al. GCN
10612) with Shajn telescope of CrAO between (UT) June, 11 20:07 --
21:50 under photometric weather conditions and mean seeing of about 2
arcsec. The preliminary photometry of the afterglow+host in a stacked
image based on USNO-B1.0 star 1014-0271368 (RA(J2000) = 17:05:26.42
Dec(J2000)= +11:27:32.9) assuming R=17.32 is following:

T0+      Filter,   Exposure,  mag.
(mid, d)              (s)

53.9919     R       88x60    22.05 +/-0.07

The brightness of the host is less but compatible with early reported
magnitudes on May 14 (R = 21.86 +/-0.06; GCN 10783) and (Rc = 21.90
+/-0.03; GCN 10794)