TITLE: GCN CIRCULAR NUMBER: 27464 SUBJECT: GRB 200325B: Tautenburg observations DATE: 20/03/28 20:01:16 GMT FROM: Sylvio Klose at TLS Tautenburg S. Klose, B. Stecklum, A. Nicuesa Guelbenzu, S. Melnikov, and F. Ludwig (all Tautenburg) report: We observed the field of GRB 200325B (Ferni GBM team, GCN 27441) with the Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6k x 6k CCD camera and the wide V-band filter (VB). The transmission curve of this filter closely follows the Gaia GBP filter. Observations were performed during several epochs starting 1.2 days after the burst. The optical transient discovered by the MASTER Global Robotic Net (Lipunov et al., GCN 27446) is clearly detected (see also Pozanenko et al., GCN 27452; Belkin et al., GCN 27455; Strausbaugh et al., GCN 27456; D'Avanzo et al., GCN 27457). Aperture photometry was performed using several Gaia DR2 stars in the field. Between dt = 1.2 and 2.4 days the optical transient was fading by 1.3 mag. During our last observation (2.4 days post burst) it had reached VB = 20.7 +/- 0.2 mag.