[AAVSO-HEN] GRB 070411: Optical photometry at Crni Vrh

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  6288
SUBJECT: GRB 070411: Optical photometry at Crni Vrh
DATE:    07/04/12 13:15:01 GMT
FROM:    Herman Mikuz at OCV  <herman.mikuz at fmf.uni-lj.si>

H. Mikuz, J. Skvarc and B. Dintinjana on behalf of PIKA observing program at
Crni Vrh Observatory:

Following the GCN 6270, we performed the analysis of images, obtained with
R and B photometric filters. Photometry results are given in table below.
Time refers to exposure start.

Time (UT)    h  m  s    Exposure (s)  Mag.   Err.  Filter
2007 Apr 11 20:14:00.8      90        18.7   0.2   R
2007 Apr 11 20:19:31.8      90        18.2   0.2   R
2007 Apr 11 20:25:02.7      90        18.4   0.2   R
2007 Apr 11 20:30:33.6      90        18.8   0.3   R
2007 Apr 11 20:36:04.3      90        19.7   0.7   R
2007 Apr 11 20:41:35.2      90        not detected R

2007 Apr 11 20:16:00.9     180        19.9   0.7   B
2007 Apr 11 20:21:32.0     180        19.1   0.3   B
2007 Apr 11 20:27:03.0     180        19.3   0.3   B
2007 Apr 11 20:32:33.9     180        19.9   0.6   B
2007 Apr 11 20:38:04.6     180        not detected B
2007 Apr 11 20:43:35.3     180        not detected B

The magnitudes are derived using comparison stars from the USNO-B1
catalogue. The 3-sigma limiting magnitude in R filter is around magnitude
19.8, and about 20.0 in B filter. Fits images are available at
http://www.observatorij.org/Data/GRB/2007-04-11/GRB070411.tgz