TITLE: GCN CIRCULAR NUMBER: 21060 SUBJECT: LIGO/Virgo G284239: Identification of a GW Burst Candidate DATE: 17/05/03 14:54:04 GMT FROM: Alan Weinstein at Caltech/LIGO The LIGO Scientific Collaboration and Virgo Collaboration report: The oLIB Burst analysis (Lynch et al, arXiv:1511.05955) identified candidate G284239 during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2017-05-02 22:26:07.910 UTC (GPS time: 1177799185.910). G284239 is a low-significance short-duration burst candidate. Its false alarm rate, as determined by the online analysis, is 1.26e-07 Hz or about 4 per year. The event's properties can be found at this URL: https://gracedb.ligo.org/events/G284239 No other GW event candidates were identified within a 300 s window before or after G284239. A sky map, LIB_skymap.fits.gz, is available to be retrieved from the GraceDB event page. This is the preferred sky map at this time. The 50% confidence region covers 1029 squares degrees and the 90% confidence region covers 3593 square degrees. The GCN Notice and Circular were delayed by more than 16 hours due to a technical problem, now resolved. Updates on our analysis of this event will be sent as they become available.