TITLE: GCN CIRCULAR NUMBER: 29604 SUBJECT: GRB 210306A: Tautenburg observations DATE: 21/03/06 17:15:56 GMT FROM: Sylvio Klose at TLS Tautenburg B. Stecklum, S. Klose, A. Nicuesa Guelbenzu, S. Melnikov, and S. Hoegner (all Tautenburg) report: We observed the field of GRB 210306A (D'Elia et al., GCN 29597) with the Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6kx6k CCD camera. Between 4:29 UT and 4:48 UT the afterglow was fading from R=17.33 +/- 0.02 to 17.53 +/- 0.09 mag (Vega), calibrated against the USNO B1 star at R.A., Decl. (J2000) = 129.924281, +60.163889 (DS9, R2mag = 15.23) close to the afterglow position.