{
  "bibcode": "2019GCN.24313....1S",
  "body": "B. J. Shappee (IfA-Hawaii), C. S. Kochanek (OSU), K. Z. Stanek (OSU), S.\nHolmbo (Aarhus), A. Franckowiak (DESY), T. W.-S. Holoien (Carnegie\nObservatories), J. L. Prieto (Diego Portales; MAS), Subo Dong (KIAA-PKU),\n T. A. Thompson (OSU), J. F. Beacom (OSU)\n\n\nSwift reported a possible counterpart (Breeveld et al., GCN #24296) to\nLIGO/Virgo\nAlert GCN #24168 of a BNS merger.  The reported detection was acquired\non 2019-04-26.784282\nUT Swift UVOT u=17.74 +/- 0.18 mag (Vega). ZTF (Andreoni et al., GCN #24302\n) reported non-detections 9 hours before the reported Swift observations.\n\n\nASAS-SN observations cover both 7 hours before and 12 hours after the\nreported Swift transient with 3-sigma g-band limits deeper than the\nreported u-band detection:\n\n2019-04-25.4180376   >18.755\n\n2019-04-26.4875420   >18.749\n\n2019-04-27.3040667   >18.421\n\n\n\nThe transient Swift observed must have evolved on a short timescale or have\nbeen very blue (u-g)~-1.\n\n\n\nWe would like to thank Las Cumbres Observatory and its staff for their\ncontinued support of ASAS-SN. ASAS-SN is funded in part by the Gordon and\nBetty Moore Foundation through grant GBMF5490 to the Ohio State University,\nNSF grant AST-1515927, the Mt. Cuba Astronomical Foundation, the Center for\nCosmology and AstroParticle Physics (CCAPP) at OSU, the Chinese Academy of\nSciences South America Center for Astronomy (CASSACA), and the Villum\nFonden (Denmark). For more information about the ASAS-SN project, see\nhttp://www.astronomy.ohio-state.edu/asassn/index.shtml.",
  "circularId": 24313,
  "createdOn": 1556411214000,
  "email": "shappee@hawaii.edu",
  "subject": "LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient in ASAS-SN observations hours before and after discovery",
  "submitter": "Benjamin Shappee at U. of Hawaii  <shappee@hawaii.edu>",
  "eventId": "LIGO/Virgo S190425z"
}