[vsnet-grb-info 5285] Optical observations of GRB 071020

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6981
SUBJECT: Optical observations of GRB 071020
DATE:    07/10/23 11:25:46 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt at aavso.org>

Veli-Pekka Hentunen (Taurus Hill Observatory, Varkaus, Finland) reports to 
the AAVSO International High Energy Network the following optical 
observations of GRB071020 (GCN #6979, Holland et al.):

Markku Nissinen, Henri Taino and Veli-Pekka Hentunen report the detection 
of the optical afterglow of GRB 071020 (Holland et al., GCN 6949; Schaefer 
et al., GCN 6948; Yuan et al., GCN 6951; Xin et al., GCN 6956). The 
afterglow was observed unfiltered approximately 17 hours post-burst, using 
a 0.3-meter Meade LX200 at Taurus Hill Observatory.  The source was 
detected with marginal signal to noise at an unfiltered magnitude of 20.9 
+/- 0.3, with an observational mid-point time of 2007 October 20, 23:54:37 
UT.  The magnitude is calibrated relative to GSC 0247201072 (GSC1.2) with 
a magnitude of 13.54.  The afterglow magnitude is consistent with an 
earlier observation by Xin et al. (GCN 6956) as well as with a later 
observation by Im et al. (GCN 6970).

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