[vsnet-grb-info 25475] GRB 200412B: Tautenburg observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27575
SUBJECT: GRB 200412B: Tautenburg observations 
DATE:    20/04/14 10:45:57 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose at tls-tautenburg.de>

S. Klose, B. Stecklum, S. Melnikov, and A. Nicuesa Guelbenzu (all 
Tautenburg) report:

We continued observing the field of GRB 200412B (Fermi GBM team, GCN 
27547) with the Tautenburg 1.34m Schmidt telescope equipped with the 
TAUKAM 6k x 6k CCD camera and the wide V-band filter (VB; Stecklum et al., 
GCN 27567).

For the optical transient (Lipunov et al., GCN 27555, 27556) at a mean 
time APR 13, 21:08:59 UT (1.500 days post burst) we measure VB = 20.27 +/- 
0.03. Compared to our 1st-epoch observations (dt=0.51 days; Stecklum et 
al., GCN 27567) this provides a decay slope of alpha = 1.58 (F\nu \propto 
t**(-\alpha)), in agreement with the results reported by Xin et al. (GCN 
27571) and Belkin et al. (GCN 27574).