[vsnet-grb-info 14109] GRB 131030A: P60 observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15423
SUBJECT: GRB 131030A: P60 observations
DATE:    13/11/01 00:48:58 GMT
FROM:    Daniel Perley at Caltech  <dperley at astro.caltech.edu>

D. A. Perley (Caltech) and S. B. Cenko (NASA/GSFC) report on behalf of a
larger collaboration:

We observed the afterglow of GRB 131030A (GCN 15402, Troja et al.) with 
the robotic Palomar 60-inch telescope in the g, r, i, and z filters. 
Three exposures of 180 seconds each were acquired in each filter at four 
separate epochs starting at 5.09, 6.63, 8.12, and 9.65 hours after the 
Swift trigger, respectively.  The light curve in these bands shows a 
steady power-law decline with decay index alpha~0.95, similar to that 
reported by RATIR over the same timescale (GCN 15420, Littlejohns et al.)

Photometry from the first epoch (calibrated relative to SDSS) yields:

t_mid(d) exp(s) filter   magnitude
0.21434  3x180    g  = 19.14 +/- 0.02
0.21912  3x180    r  = 18.81 +/- 0.02
0.22391  3x180    i  = 18.61 +/- 0.03