TITLE:   GCN CIRCULAR
NUMBER:  7090
SUBJECT: GRB 071112C: optical observation
DATE:    07/11/14 19:45:18 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Stefano Sposetti (Gnosca, Switzerland) reports to the AAVSO
International High Energy Network the following optical observations of
GRB071112C (GCN #7059, Perri et al.):

Stefano Sposetti reports the detection of the optical afterglow of
GRB071112C (Perri et al., GCN 7059, and several subsequent reports). 
The afterglow was observed unfiltered for 2700 seconds, using a
0.4-meter Newtonian with an SBIG ST8XE CCD and no filter.  Observations
commenced approximately 4 hours and 10 minutes post BAT detection; the
midpoint of the observational sequence was 2007 November 12.9625 UT. The
afterglow was detected at an unfiltered magnitude of 21.0 +/- 0.5,
calibrated relative to USNO-A2.0.  This magnitude is consistent with the
reported detection by Greco et al. (GCN #7089) on November 12.929 UT at
Rc = 21 +/- 0.2.

A detailed report on these observations is available on the AAVSO website
at ftp://ftp.aavso.org/grb/StefanoSposetti_GRB071112C_2454419.20588_.txt

A fits image is available at
ftp://ftp.aavso.org/grb/StefanoSposetti_GRB071112C_2454419.20588_.fits

The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.