GCN Circular 4981
Subject
GRB 060418: JHKs PAIRITEL Observations of Afterglow
Event
Date
2006-04-20T00:06:36Z (20 years ago)
From
Daniel Kocevski at UC Berkeley <kocevski@berkeley.edu>
Daniel Kocevski, J. S. Bloom (UC Berkeley), and C. H. Blake (Harvard/
CfA), on behalf of a larger collaboration, report:
"We began observations of GRB 060417 (Falcone et. al. GCN 4966) with
the PAIRITEL 1.3m at 2006-04-18 05:25:34. UTC, 2hr32min after the GRB
trigger. The transient reported by Falcone et al. (GCN 4966) is well
detected in 300s mosaics simultaneously in JHKs bands, and is seen to
fade between mosaics. A series of 13 simultaneous JHKs mosaics taken
over 6 hours of observations shows a power law decline in J with a
slope of about alpha = 1.11 +/- 0.10 ( F(t)~t^(-alpha) ). The decay
slopes measured in H and Ks are consistent with the J band slope
within error. This slope is consistent with that reported by
Nysewander et al. (GCN 4971) and Cobb et al. (GCN 4972). No break
was seen in the observed decay out to at least 08:09:31 UTC.
An animated gif of the observations can be found at:
http://lyra.berkeley.edu/~kocevski/GCN/GRB060418.gif
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