{
  "bibcode": "2019GCN.25963....1B",
  "body": "S. Belkin (IKI), A. Pozanenko (IKI), M. Krugov (AFIF), E. Mazaeva (IKI), \nA. Volnova (IKI) report on behalf of IKI-FuN follow-up collaboration:\n\nWe observed  the Swift J221951-484240 blue Optical Transient (Oates et \nal., GCN 25901; Oates et al., GCN 25939)   in the field of the \nLIGO/Virgo S190930t (LIGO Scientific Collaboration and the Virgo \nCollaboration, GCN  25876). Several images were obtained in r' -filter \nof RC-1000 telescope. The OT was also previously observed by Kamei et \nal. (GCN 25941) and Buckley et al. (GCN 25962). Preliminary photometry \nof  the Swift J221951-484240 OT  is following.\n\nDate       UT start MJD         Filter Exp.  OT    Err.  UL\n                     (mid, days)        (s)\n\n2019-10-05 04:22:44 58761.19808  r'    2700  19.35 0.06  22.7\n\nThe photometry is based on the USNO-B1.0 stars (reverse Lupton's \ntransformation VRI -> r)\n\n  USNO-B1.0_id r_Sloan(Lupton)\n  0412-0779298 16.866\n  0412-0779234 17.469\n  0413-0785834 16.580\n  0413-0785834 17.565\n  0413-0785847 16.517",
  "circularId": 25963,
  "createdOn": 1570386477000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "LIGO/Virgo S190930t: Swift J221951-484240 optical photometry of Chilescope observatory",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "LIGO/Virgo S190930t"
}