{
  "body": "A. Moskvitin (SAO RAS), N. Pankov (IKI), A. Pozanenko (IKI),\nA. Volnova (IKI), V. Vlasyuk (SAO RAS), O. Spiridonova (SAO RAS),\nV. Goranskij (SAI MSU, SAO RAS), N. Pit (CrAO), V. Rumyantsev (CrAO),\nI. Nikolenko (INASAN) on behalf of IKI-GRB-FuN.\n\nWe continue R-band observations of the GRB 260610B (The Fermi GBM team,\nGCN 44891; GCN 44901; Godwin and Meegan, GCN 44931; Yu et al.,\nGCN 44944) on June 17--20, 22--25 and 27 nights with the 1-m\nZeiss-1000, the 0.5-m AS-500 (2) telescopes of SAO RAS,\nthe 1.25-m AZT-11 telescope of CrAO and the 1-m Zeiss-1000/Koshka\ntelescope of INASAN.\n\nThe OT (O'Neill et al., GCN 44903; Watson et al., GCN 44905;\nZhu et al., GCN 44909; Gillanders et al., GCN 44910; Akl et al.,\nGCN 44911; O'Neill et al., GCN 44914; Moskvitin et al., GCN 44918;\nJackson-Horne et al., GCN 44919; Izzo, GCN 44920; Li et al.,\nGCN 44921; Bochenek and Perley, GCN 44927; Moskvitin et al., GCN 44929;\nAkl et al., GCN 44930; Bochenek and Perley, GCN 44932; Pankov et al.,\nGCN 44946; Gillanders et al., GCN 44955; Angulo et al., GCN 44958;\nDimple et al., GCN 44959; Moskvitin et al., GCN 44963; Pankov et al.,\nGCN 44977; Gassert et al., GCN 44981; Gupta et al., GCN 44993;\nCorcoran et al., GCN 45004; Simon et al., GCN 45007) is clearly\ndetected in the stacked images derived from our observations\n(except AZT-11 observations on 2026-06-22 and Zeiss-1000/Koshka\ndata obtained on 2026-06-24, 2026-06-25, 2026-06-27).\n\nThe observational log is provided below:\n\nDate       UTstart  Exposure, s Filter Site    Telescope\n---------- -------- ----------- ------ ------- ----------\n2026-06-17 20:12:50  3600       R      SAO RAS AS-500\n2026-06-17 19:28:53  2700       R      CrAO    AZT-11\n2026-06-18 19:46:46  5400       R      SAO RAS AS-500\n2026-06-18 20:01:52  3600       Rc     SAO RAS Zeiss-1000\n2026-06-19 18:56:04  1800       R      CrAO    AZT-11\n2026-06-20 21:36:05  5400       R      SAO RAS AS-500\n2026-06-22 20:04:20  3600       R      CrAO    AZT-11\n2026-06-22 22:24:19  2880       Rc     SAO RAS Zeiss-1000\n2026-06-23 19:03:08  9660       R      SAO RAS AS-500\n2026-06-24 19:37:50 14400       R      INASAN   Zeiss-1000/Koshka\n2026-06-25 21:47:04  5400       R      SAO RAS AS-500\n2026-06-25 19:16:02 14400       R      INASAN   Zeiss-1000/Koshka\n2026-06-27 19:39:42  8100       R      INASAN   Zeiss-1000/Koshka\n\nA preliminary light curve constructed from observations is available at:\nhttps://heaiki.ru/lvc/r/GRBs/GRB260610B/GRB260610B_LC1.jpg\nBesides of the relatively fast brightening started at about 5 days\nafter trigger (Gillanders et al., GCN 44955; Angulo et al., GCN 44958;\nDimple et al., GCN 44959; Moskvitin et al., GCN 44963; Gupta et al.,\nGCN 44993; Corcoran et al., GCN 45004; Simon et al., GCN 45007)\nwe note slow fading till 15th day. The absolute magnitude\nand time of maximum (assuming redshift of z = 0.473 the absolute\nmagnitude is about M_R = -20.8) do not contradict that brightening\ncould be a manifestation of a supernova.\n",
  "createdOn": 1782894923083,
  "subject": "GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve",
  "submittedHow": "email",
  "circularId": 45062,
  "eventId": "GRB 260610B",
  "submitter": "Alexander Moskvitin at SAO RAS <mosk@sao.ru>"
}