{
  "bibcode": "2025GCN.41428....1M",
  "submittedHow": "web",
  "subject": "GRB 250818B: SAO RAS optical observations",
  "body": "A. Moskvitin, O. Spiridonova, V. Vlasyuk, Yu. Sotnikova (SAO RAS), \nTao An and Yuanqi Liu (Shanghai Astronomical Observatory) report\non behalf of a larger collaboration.\n \nWe observed the field of the SVOM short GRB 250818B (Wang et al., \nGCN 41405; also detected by Swift/XRT, Ferro et al., GCN 41407\nand EP-FXT, Li et al., GCN 41424) with the 1-m SAO RAS telescope \nZeiss-1000 equipped with CCD-photometer. We obtained 13 x 300 sec. \nimages in Rc band on August 18, 23:15:02 -- August 19, 00:33:37 UT \n(t_mid - T0 = 20.4196 hours = 0.85082 days).\n\nThe OT (Kumar et al., GCN 41406; Yao et al., GCN 41409; Zheng et al., \nGCN 41417; Fong et al., GCN 41419; Bendtsen et al., GCN 41426) \nis clearly detected in the stacked image with the brightness of \nR = 20.88 +/- 0.04 (R_lim = 23.0).\n\nThis preliminary photometry is based on nearby Pan-STARRS objects \n(magnitudes were converted with the Lupton 2005 equations) \nand not corrected for Galactic extinction.",
  "createdOn": 1755591213685,
  "eventId": "GRB 250818B",
  "format": "text/plain",
  "submitter": "Alexander Moskvitin at SAO RAS <mosk@sao.ru>",
  "circularId": 41428
}