GCN Circular 29273
Subject
GRB 210104A: SARA-KP 0.9m Optical Afterglow Detection
Event
Date
2021-01-06T22:01:36Z (5 years ago)
From
Samalka Anandagoda at Clemson University <iananda@g.clemson.edu>
S. Anandagoda, S. Geier, K. Pellegrin and D. Hartmann report:
We observed the field of GRB 20210104A (Fermi GBM Team, GCN 29232; Troja et al., GCN 29233; Biltzinger et al., GCN 29234) using the SARA 0.9m optical telescope located at Kitt Peak, AZ, USA, equipped with the Alta-E6-1105 camera. Observation started at 06:20:04 UTC on 2021-01-05 and ended at 09:34:43 UTC (~ 18 to 21 hours after the detection of the burst by the Fermi GBM Team). We obtained a series of 120s exposure frames in the Bessell R filter. We clearly detect the optical afterglow of GRB 20210104A at the enhanced Swift-XRT position (Beardmore et al., GCN 29245).
The estimated magnitude of the GRB afterglow was 20.61 found by stacking 20 images of 120s each in the Bessell R band filter.
T_start-T0 (hrs) T_end-T0 (hrs) Start Date (UTC) Filter Magnitude (mag)
���������������������������������������������������������������������������������������-------------------------
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18:53 19:33 2021-01-05T06:20:04 R 20.61
Photometry is done based on the USNO-B1.0 catalog.
The Southeastern Association for Research in Astronomy (SARA) consortium operates three telescopes: the 0.9-m SARA-KP at Kitt Peak in Arizona, and the 0.6-m SARA-CT at Cerro Tololo in Chile, and the 1.0-m SARA-RM (formerly the JKT) telescope at Roque de los Muchachos Observatory in the Canary Islands. For more information see: Keel et al. (2016): https://iopscience.iop.org/article/10.1088/1538-3873/129/971/015002