TITLE: GCN CIRCULAR NUMBER: 23870 SUBJECT: GRB 190202A: SAO RAS further optical observations DATE: 19/02/04 19:53:15 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin, O. I. Spiridonova, O. A. Maslennikova (SAO RAS), and A. A. Volnova (IKI RAS) report on behalf of larger collaboration. We observed the field of the GRB 190202A (Lien et al., GCNC #23830) with the Zeiss-1000 telescope of SAO RAS (+ CCD photometer) on February, 3, 21:15:42--22:45:25 UT (mid. time 22:00:33). The observations were carried out in Rc band. We detected the OT (Novichonok et al., GCNC #23831; Steeghs et al., GCNC #23833; Paul Kuin & A. Y. Lien, GCNC #23834; Cucchiara, GCNC #23839; Paek et al., GCNC #23841; Malesani et al., GCNC #23842; Belkin et al., 23843; Moskvitin & Spiridonova, GCNC #23844; Brajesh Kumar et al., GCNC #23853) in the stacked 15 x 300 sec image. Preliminary brightness of OT is R = 21.9 +/- 0.1 (T-T0 = 1.848 d). The calibrations is based on nearby SDSS stars, magnitudes converted with the Lupton 2005 equations.