[vsnet-grb-info 13664] GRB 130702A: Continued P60 observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14981
SUBJECT: GRB 130702A: Continued P60 observations
DATE:    13/07/04 08:05:48 GMT
FROM:    Daniel Perley at Caltech  <dperley at astro.caltech.edu>

D. A. Perley, L. P. Singer (Caltech), and S. B. Cenko (GSFC) report:

We obtained additional observations of the location of the probable 
afterglow of GRB 130702A with the Palomar 60-inch robotic telescope.  A 
series of repeated imaging sequences were taken in B, g, r, i, and z 
filters during intermittent clouds.  Example photometry from one 
sequence is as follows:

  tstart(d)  exp(s) filt mag        unc
  2.20405    120     i = 19.129 +/- 0.05
  2.20565    120     r = 19.297 +/- 0.05
  2.20728    120     B = 19.635 +/- 0.07
  2.20888    120     z = 19.204 +/- 0.16
  2.21048    120     g = 19.519 +/- 0.08

Compared to our previous night's P60 observations (Singer et al., GCN 
14967) and referenced to the GBM trigger time (Collazzi et al., GCN 
14972), the fading is consistent with a power law with decay index of 
approximately alpha=1.1, steeper than that inferred during the first 24 
hours.