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GCN Circular 3925

GRB 050904: More SOAR
2005-09-06T09:06:47Z (19 years ago)
Daniel E. Reichart at U.North Carolina <>
C. MacLeod, J. Kirschbrown, D. Reichart, E. Cypriano, P. Ugarte, A.
Alvarez, E. Figueredo report on behalf of the UNC team of the FUN GRB

We continued observations of the afterglow (Haislip et al., GCN 3913) of
GRB 050904 (Cummings et al., GCN 3910) with 4.1m SOAR at CTIO in J,
beginning 52.9 hours after the burst.

The afterglow is no longer detected: J > 21.6 (2 sigma).  This implies that
temporal index has steepened from -1.0 +/- 0.1 (Haislip et al., GCN 3919)
to <-2.3 over the past day, which suggests that we are now past the
jet-break time.
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