[vsnet-grb-info 4898] GRB 070714 ( Bastille ): Optical Pre-Imaging

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6624
SUBJECT: GRB 070714 ("Bastille"): Optical Pre-Imaging 
DATE:    07/07/14 22:47:19 GMT
FROM:    Josh Bloom at UC Berkeley  <jbloom at astron.berkeley.edu>

P. Nugent (LBL) and J. S. Bloom (UC Berkeley) report:

We have created a stacked image through the co-addition of 8  
unfiltered images taken by the NEAT collaboration and 51 images in  
the RG610 filter taken by the Palomar-Quest Consortium at the Palomar  
Oschin Schmidt telescope (obtained from 2002-2006), of what is being  
called a short-hard burst (SHB) 070714A (Barbier et al.; GCN #6622).  
The stacked image is significantly deeper than the DSS (3 sigma limit  
of R~22.7 mag). There is no source at the position of the proposed  
counterpart (Melandri et al. GCN #6621). Since this Liverpool  
Telescope source was detected in twilight, it was likely seen near  
the DSS limit (or brighter) and thus, while we cannot say for sure  
(since no magnitude was given in GCN #6621), the absence of a  
similarly bright source in our image suggests that the Melandri et  
al. source was indeed the afterglow.

Note that the source @ position RA = 03:51:21.24, DEC = +28:17:45.5  
is in the 2MASS catalog and is blue (J - K = 0.5 mag).

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