TITLE: GCN CIRCULAR NUMBER: 24462 SUBJECT: LIGO/Virgo S190510g: Updated classification and data quality report DATE: 19/05/10 20:56:46 GMT FROM: Shasvath J. Kapadia at U. of Wisconsin, Milwaukee The LIGO Scientific Collaboration and the Virgo Collaboration report: We continue analyzing the LIGO and Virgo data around the time of the Compact Binary Coalescence (CBC) candidate S190510g (GCN 24442 and GCN 24448): https://gracedb.ligo.org/superevents/S190510g/ A new version of the classification estimation code, which better accounts for the significance of the event using detection-pipeline-specific foreground and background models, was applied to the data. This yields the following updated classification of the GW signal, in order of descending probability: BNS (85%), Terrestrial (15%), NSBH (<1%), BBH (<1%), or MassGap (<1%). This new version of the classification estimation code will be deployed in the front-end of the low latency pipelines on the next detector maintenance intervention on Tuesday, May 14th 2019 15:00UTC. Continued examination of this event also revealed there are data quality issues and non-stationary noise behavior around the time of the event. Its significance may decrease as our estimate of the background improves. If the event is astrophysical, the currently preferred skymap still represents our best estimate of source location. However, the noise characteristics around the time of the event could bias such localizations. Further analysis of the event is ongoing. For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo Public Alerts User Guide .