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GCN Circular 12190

GRB 110709B / EVLA detection of radio counterpart
2011-07-21T22:04:14Z (13 years ago)
Ashley Zauderer at CfA <>
A. Zauderer and E. Berger (Harvard/CfA) report on behalf of a larger 

"We observed GRB 110709B (GCN 12122) with the EVLA on several occasions 
between 2011 July 11 and 16 UT at a frequency of 5.8 GHz.  Within the 
XRT error circle (GCN 12136) we find a single unresolved radio source 
which brightened by about a factor of 1.6 between 2.1 and 7.0 days after 
the burst.  The source is located at (J2000):

RA =   10:58:37.114
Dec = -23:27:16.760

The coincidence with the XRT position and the rising flux indicate that 
this source is the radio afterglow of GRB 110709B.  No optical 
counterpart is detected at this position in our Gemini r-band 
observations (GCNs 12132, 12155) to a limit of >23.8 mag at 3.2 hours 
and >25.1 mag at 4.1 days.  Along with the bright X-ray counterpart, the 
radio source provides additional support that GRB 110709B is a dark burst.

We thank the EVLA staff for their support of these observations."
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