GCN Circular 31285
Subject
GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
Date
2021-12-23T04:17:37Z (2 years ago)
From
Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh@nu.edu.kz>
T. Komesh (NU), B. Grossan (UCB, NU), Z. Maksut (NU), M. Krugov (FAI),��
E. Linder (UCB, NU), E. Abdikamalov (NU), G. F. Smoot (HKUST, UCB, NU),
report on behalf of the Energetic Cosmos Laboratory:
The Nazarbayev University Transient Telescope at Assy-Turgen
Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB
211221A 19 s after receipt an automated GCN / BAT position alert,
observing in Sloan i' band, with the Burst Simultaneous Three-Channel
Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14).
We started observations at 20:51:35 UT on 2021-12-21, 175 s after the
BAT trigger. Observations were made in clear conditions starting at
about 30 deg. target altitude. No source consistent with the XRT (P.
Evans et al., GCN Circ. 31275) was detected.�� We report the following
results:
start time������ t-t0(s)�� end time�������������� ULi'������������ exposure_time (s)
------------������ --------�� ------------������������������ ------ --------------------
20:51:35 ������ 175 �� 20:52:35 ���������������� 17.9 ������������������ 60
20:52:50 ������ 257 �� 22:12:50 ���������������� 18.4 �������������� 150
start time is in UT. t-t0(s) gives the time since trigger, in seconds.
UL i', gives the 5 sigma upper limit sensitivity in magnitudes, for
images co-added to the given exposure time. The first row in the table
corresponds to co-adds of an initial short exposure image sequence of
7.5 s. The second row corresponds to co-adds from a continuing series of
15 s exposures.�� Calibration was done with the 3 bright Pan-STARRS
catalog stars on our images.
We caution the reader that these are preliminary results, without color
or other corrections. Please also note that times are approximate.
----------------------------------
NU = Nazarbayev University, Nur-Sultan, Kazakhstan
UCB = University of California, Berkeley, USA
HKUST = Hong Kong University of Science and Technology
FAI = Fesenkov Astrophysical Institute, Kazakhstan
The NUTTelA-TAO Team acknowledges the support of the staff of the
Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the
Fesenkov Astrophysical Institute, Almaty, Kazkhstan.