[vsnet-grb-info 2534] GRB 051221: No variability in Gemini data

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4371
SUBJECT: GRB 051221: No variability in Gemini data
DATE:    05/12/21 08:18:37 GMT
FROM:    Edo Berger at Carnegie Obs  <eberger at ociw.edu>

E. Berger (Carnegie Observatories) reports:

"Further analysis of the Gemini GMOS data reveals that the object located
within the XRT error circle (GCNs 4367-9) has not changed in brightness
between 227 and 271 min after the burst to a limit of about 0.05 mag in
comparison to several nearby stars.  We note that a typical decay rate of
t^-1 would result in a change of about 0.2 mag.  The lack of variability 
suggests that this is either the host galaxy or an unrelated object, or 
that the decay rate is unusually shallow, |alpha|<0.25."