{
  "submittedHow": "web",
  "bibcode": "2025GCN.42399....1M",
  "format": "text/plain",
  "subject": "GRB 251013C: further SAO RAS optical observations",
  "eventId": "GRB 251013C",
  "circularId": 42399,
  "submitter": "Alexander Moskvitin at SAO RAS <mosk@sao.ru>",
  "createdOn": 1761230646177,
  "body": "A. S. Moskvitin, O. I. Spiridonova, V. V. Vlasyuk (SAO RAS) \nreport on behalf of GRB follow-up collaboration.\n\nWe observed the field of the GRB 251013C (The Fermi GBM team, \nGCN 42221; Rakotondrainibe et al., GCN 42222) with the 1-m SAO RAS \ntelescope Zeiss-1000 equipped with the CCD-photometer \non October 20 and 21 nights.\n\nThe optical afterglow (Palmerio et al., GCN 42223; \nPerez-Garcia et al., GCN 42225; Konno et al., GCN 42226; \nMartin-Carrillo et al., GCN 42227; Masi, GCN 42228; Palmerio et al., \nGCN 42229; Moskvitin et al., GCN 42230; Gompertz et al., GCN 42231; \nLipunov et al., GCN 42235; Garnavich, GCN 42240; Watson et al., \nGCN 42241; López-Cámara et al., GCN 42242; Brosio et al., GCN 42251; \nReguitti, GCN 42253; Quintana-Ansaldo et al., GCN 42254; \nMaksut et al., GCN 42256; Ghosh et al., GCN 42261; Quadri et al., \nGCN 42262; Adami et al., GCNs 42266, 42276, 42338; Peretto et al., \nGCN 42267; Ruocco et al., GCN 42269; Calapai, GCN 42275; \nGlobus et al., GCN 42279; Evans, GCN 42281; Abidkhanov et al., \nGCN 42283; Siegel, GCN 42298; Leonini et al, GCN 42301; Méndez et al., \nGCN 42318; He et al., GCN 42319; Pavoni et al., GCN 42333; Bochenek \nand Perley, GCN 42334; Volnova et al., GCN 42396) is clearly detected \nin the stacked images with the following brightness.\n\nDate        UT start  t-T0     Exp.  Filter  OT     Err.    UL\n                      (mid, d) (s)    \n2025.10.20 19:59:38   7.12682  13 x 300  Rc  21.61 +/- 0.11 22.7\n2025.10.21 17:02:31   8.01103  19 x 300  Rc  21.80 +/- 0.10 23.0\n\nPreliminary photometry is based on the nearby SDSS objects\n(magnitudes converted with Lupton 2005 equations)\nand has not corrected for the Galactic extinction."
}