{
  "bibcode": "2025GCN.39576....1M",
  "eventId": "EP250302a",
  "submittedHow": "web",
  "circularId": 39576,
  "submitter": "Moskvitin Alexander at SAO RAS <mosk@sao.ru>",
  "createdOn": 1741019579242,
  "format": "text/plain",
  "body": "A. S. Moskvitin, O. A. Maslennikova (SAO RAS), A. Pozanenko (IKI) \nand N. Pankov (HSE, IKI) report on behalf of larger collaboration.\n\nWe observed the field of the X-ray transient EP250302a (Dai et al., \nGCN 39556; Page et al., GCN 39557) with SAO RAS 1-m telescope \nZeiss-1000 equipped with CCD-photometer under mediocre weather \nconditions. We obtained two sets of 300-sec images in Rc band.\n1st set: 2025.03.02, 20:33:49 -- 2025.03.02, 22:09:49 UT \n(t_mid - T0 = 0.24010 days = 5.7625 hours);\n2nd set: 2025.03.02, 23:55:53 -- 2025.03.03, 01:00:10 UT, \n(t_mid - T0 = 0.36942 days = 8.8660 hours).\n\nThe OT (Zhu et al., GCN 39550; Busmann et al., GCN 39551; \nLeonini et al., GCN 39553; Wu et al., GCN 39555; Xin et al., \nGCN 39558; Adami et al., GCN 39560; Yang et al., GCN 39561;\nBecerra et al., GCN 39562; Izzo et al., GCN 39564; Pankov et al., \nGCN 39565; Reguitti, GCN 39568; Komesh et al., GCN 39569; Shilling \nand Breeveld, GCN 39570; Aryan et al., GCN 39572) is clearly detected \nin our stacked frames with the following brightness.\n\nDate       UT start t-T0 (mid),d   Exp.,s  Filter OT    Err. UL(3sigm)\n2025.03.02 20:33:49 0.24010        8x300   R      20.18 0.09 22.5\n2025.03.02 23:55:53 0.36942        7x300   R      20.51 0.10 22.5\n\nAbove photometry is preliminary and calibrated against R2 magnitudes \nof nearby USNO-B1 stars and not corrected for the Galaxy extinction.",
  "subject": "EP250302a: SAO RAS optical observations"
}