{
  "bibcode": "2019GCN.25941....1K",
  "body": "Kamei, Y.; Abe, F.; Tristram, P. J. (Nagoya U.); Murata, K. L. (Tokyo Institute of Technology); Onozato, H. (U. Hyogo); Utsumi, Y. (Stanford/SLAC) on behalf of J-GEM collaboration\n\nWe report an optical follow-up observation for the electromagnetic counterpart candidate of the gravitational wave event S190930t (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN Circ. 25876) reported by Stein et al. (Oates et al., GCN Circ. 25901, 25939).\n\nWe observed one of the EM counterpart candidates of neutron star and black hole merger, Swift J221951-484240, using 61 cm Boller & Chivens telescope at Mt. John Observatory in New Zealand (B&C) and a three color imager Tripole5 (g, r, i). The brightness of the candidate on 2019-10-02 23:00:37 UTC (MJD 58758.490340) is\ng~19.6\nr~19.3\ni~19.3 \nin AB magnitude system compared with nearby stars with UCAC4 catalog (Zacharias et al. 2012).\n\nWe would like to thank observers for helping the observations.",
  "circularId": 25941,
  "createdOn": 1570132375000,
  "email": "murata@u.phys.nagoya-u.ac.jp",
  "subject": "LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240",
  "submitter": "Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>",
  "eventId": "LIGO/Virgo S190930t"
}