Dal GCN Circulars Archive della NASA



NUMBER:  17705


DATE:    15/04/15 02:02:25 GMT

FROM:    Matteo M. M. Santangelo at OAC  oac@irf.lu.it





M.M.M. Santangelo and S. Gambogi report:


We performed R and I bands CCD imagery of the field of GRB 150413A

with the 0.60-meter f/9.83 Cassegrain reflector of Capannori Astronomical Observatory, Italy.

Weather conditions were good, the seeing was fairly good, and the night-sky brightness

at zenith was 20.15 mag/arcsec2 in V band.

We clearly detected the optical counterpart of GRB 150413A.

Magnitudes in Johnson/Cousins R and I bands derived by means of Mira professional 7 UE software are as follows:


Date           UT         Exposure   Band   mag ± sigma

2015-04-13   20:56:22   300 s       I      17.2 ± 0.2

2015-04-13   21:04:43   180 s       R      17.6 ± 0.1

2015-04-13   21:11:02   360 s       I      17.29 ± 0.04


Photometry is based on the nearby GSC 4397:1311 star, with magnitudes of comparison star from PPMXL.

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