{
  "subject": "GRB 250916A: SAO RAS Zeiss-1000 optical observations",
  "bibcode": "2025GCN.41934....1M",
  "submitter": "Alexander Moskvitin at SAO RAS <mosk@sao.ru>",
  "eventId": "GRB 250916A",
  "submittedHow": "web",
  "format": "text/plain",
  "createdOn": 1758533979534,
  "body": "A. Moskvitin, O. Spiridonova (SAO), N. Pankov (HSE), A. Pozanenko \n(IKI), A. Ghosh, S. Razzaque (CAPP, University of Johannesburg), \nTao An and Yuanqi Liu (Shanghai Astronomical Observatory) \nreport on behalf of GRB follow-up collaboration and IKI-GRB-FuN.\n\nWe observed the field of the GRB 250916A (Fermi GBM team, GCN 41839; \nArya et al., GCN 41843; Cheung et al., GCN 41855; Osborne et al., \nGCN 41862; Waratkar and Grefenstette, GCN 41871; Godwin and Meegan, \nGCN 41876) with the 1-m SAO RAS telescope Zeiss-1000 equipped \nwith the CCD-photometer. We obtained 9 x 300 sec. images Rc band \non September 21, 23:36:57 -- September 22, 00:47:22 UT \n(t_mid - T0 = 5.44639 days).\n\nThe optical transient (Belkin et al., GCN 41847; Mohan et al., \nGCN 41858; Moskvitin et al., GCN 41859; Burkhonov et al., GCN 41860;\nde Ugarte Postigo et al., GCN 41863; Moskvitin et al., GCN 41870;\nZheng and Filippenko, GCN 41873; Pankov et al., GCN 41892; \nHall et al., GCN 41921) is clearly detected in the stacked frame \nwith the brightness of R = 22.6 +/- 0.1.\n\nDate        UT start  t-T0     Exp.  Filter  OT     Err. UL (3sigma)\n                      (mid, d) (s)       \n2025.09.21  23:36:57  5.44639  9 x 300 Rc  22.6 +/- 0.1 23.3\n                      \nPreliminary photometry is based on the nearby objects from PanSTARRS \n(magnitudes converted with Lupton 2005 equations) \nand has not corrected for the Galactic extinction.",
  "circularId": 41934
}