GCN Circular 17106
Subject
GRB 141121A: three epochs of SAO RAS optical observations
Event
Date
2014-11-27T18:23:54Z (12 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
A.S. Moskvitin and V.N. Komarova report on behalf of a larger team:
We observed the field of GRB 141121A (Lien et al., GCN 17075)
with the SAO RAS 1-m Zeiss-1000 telescope at three nights:
2014.11.24/25, 25/26, 26/27.
The GRB OT (Tanga et al., GCN 17078) is clearly detected
in our stacked frames each night. Our charts can be found at
ftp://ftp.sao.ru/pub/grb/GRB141121A/GRB141121A_z1000_24_25_26.jpg
We used nearby SDSS stars for calibration. The "ugriz" magnitudes
were converted to "UBVRI" with the Lupon-2005 equations. Our OT
brightness measurements are in good agreement with R-band values
estimated within the close epochs and reported in the GCN circulars:
Kuroda et al. (GCN 17098), Mazaeva et al. (GCN 17102). Our OT
magnitudes are also similar to r-band measurements by Watson et al.
(GCN 17100) and Butler et al. (GCN 17101).
Our preliminary results are presented in the following table:
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Date T-T0 UT_start-end Exp.,s R_mag
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24.942 3.782 20:14--00:59 900 20.31+/-0.09
25.956 4.796 22:16--23:38 3600 20.86+/-0.04
26.980 5.820 22:12--00:50 4800 21.36+/-0.09
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