TITLE:   GCN CIRCULAR
NUMBER:  5875
SUBJECT: GRB 061126: Possible Jet Break
DATE:    06/11/28 08:36:02 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann (TLS Tautenburg) reports:

The afterglow of GRB 061126  (Sbarufatti et al., GCN 5854, Vanden Berk et
al., GCN 5856) was observed with the Tautenburg 1.34m Schmidt telescope   
under good weather conditions.

Observations commenced at 4:14:15 UT on November 28, and consisted of 6 x
600 sec Rc band images.

The afterglow is detected in the stacked image. Comparing with the USNO-B1
catalog, I derive the following magnitude: 

R = 23.69 +/- 0.17 at 1.83656 days after the burst.

This lies significantly beneath the extrapolation (with alpha = 0.99 +/-  
0.03) of the data reported by Smith et al. (GCN 5857), Updike et al.      
(GCN 5959) and Kann & Malesani (GCN 5866), by 0.85 magnitudes.

This may suggest that a jet break has occured and the decay has thus 
become steeper.

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