TITLE:   GCN CIRCULAR
NUMBER:  10618
SUBJECT: GRB100414A: SAO RAS optical observations
DATE:    10/04/19 07:34:18 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. Moskvitin, T. Fatkhullin, V. Sokolov (SAO RAS Niznijh Arkhyz, Russia),
on behalf of a larger colaboration, report:

We observed an OT (Cucchiara & Fox, GCN Circ. 10606, 10608;
Filgas, Kruehler & Greiner, GCN Circ. 10607; Landsman & Cannizzo,
GCN Circ. 10609) of GRB 100414A with the Zeiss-1000 telescope
of SAO RAS, Russia. Observations started 87.31 hours after
the Fermi LAT and GBM triggers (Takahashi et al., GCN Circ. 10594;
Foley, GCN Circ. 10595). We obtained 12 x 300 sec images both in Rc
and V bands with the airmass 1.2-1.7 under good weather conditions.
Calibration was carried out with 8 SDSS nearby stars, whose magnitudes
were transformed according to formulae from
http://www.sdss.org/dr5/algorithms/sdssUBVRITransform.html (Lupon 2005).

Rc = 21.40 +/- 0.09 (17:39:01 -- 19:05:27 UT, mean epoch = April, 17.765),
V = 21.75 +/- 0.08 (19:08:49 -- 20:31:05 UT, mean epoch = April, 17.826).

These magnitudes are not corrected for the expected Galactic extinction
reported in Landsman & Cannizzo, GCN Circ. 10609.
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