{
  "circularId": 44395,
  "eventId": "EP260416a",
  "submittedHow": "web",
  "format": "text/plain",
  "createdOn": 1776902330253,
  "submitter": "Alexander Moskvitin at SAO RAS <mosk@sao.ru>",
  "body": "A. Moskvitin (SAO RAS), V. Rumyantsev (CrAO), A. Volnova, N. Pankov,\nA. Pozanenko (IKI), Tao An, Yuanqi Liu (SHAO), Ankur Ghosh,\nSoebur Razzaque (U. of Johannesburg, RSA) report on behalf\nof GRB follow-up collaboration.\n\nWe observed the field of EP260416a (Hu et al., GCN 44307; GCN 44324)\nwith 2.6-m ZTSh of CrAO equipped with BVRI photometer and FLI PL4240\ncamera. We obtained a series of images in R band on 2026-04-22,\n21:11:50--22:14:42 UT (t_mid - T0 = 6.6762 days).\n\nThe optical transient discovered by COLIBRÍ (Ducoin et al., GCN 44310;\nand also observed by Li et al., GCN 44315; Hua et al., GCN 44318;\nLee et al., GCN 44319; Martin-Carrillo et al., GCN 44328; Li et al.,\nGCN 44334; He et al., GCN 44336; An et al., GCN 44339; Jelinek et al.,\nGCN 44341; Guziy et al., GCN 44351; Ho et al., GCN 44354) is clearly\ndetected in the stacked image with the following brightness.\n\nDate,      UT_start,  t_mid - T0, filter,  exp,   mag    +/- err   UL\n                      days                 s    \n \n2026-04-22T21:11:50  6.67620      R       30*120  23.12 +/- 0.17  24.1\n\nThis preliminary photometry is based on the nearby USNO-B1 stars\nand not corrected for the Galactic extinction.\n",
  "subject": "EP260416a: ZTSh R band observations"
}