[vsnet-grb-info 28525] GRB 210807A: Tautenburg observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30628
SUBJECT: GRB 210807A: Tautenburg observations
DATE:    21/08/11 11:37:11 GMT
FROM:    Ana Nicuesa at TLS Tautenburg  <ana at tls-tautenburg.de>

S. Schmidl, A. Nicuesa Guelbenzu, S. Klose, S. Melnikov, B. Stecklum, U.
Laux (all Tautenburg) and J. Greiner (MPE Garching) report:


We observed the field of GRB 210807A (Lien et al., GCN 30600) with the
Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6kx6k CCD
camera.

Observations started at 23:19 UT on August 7, about 13 hours after the GRB
trigger. For the optical afterglow (Lien et al., GCN 30600; Hu et al., GCN
30602; LaPorte et al. GCN 30618) we measure the following magnitudes:

r = 21.66 +/- 0.18, at a midtime of August 7, 23:28 UT,
i = 21.25 +/- 0.19, at a midtime of August 8, 01:16 UT,
z = 20.52 +/- 0.19, at a midtime of August 8, 01:26 UT.

Second-epoch observations were performed the following night.
The optical transient was not detected anymore:

r  22.2, at a midtime of August 8, 23:34 UT,
i  22.4, at a midtime of August 9, 00:38 UT,
z  21.2, at a midtime of August 9, 01:20 UT.

Given magnitudes are calibrated against the Pan-STARRS catalogue.