GCN Circular 34366

The LIGO Scientific Collaboration, the Virgo Collaboration, and the
KAGRA Collaboration report:

We identified the unmodeled transient candidate S230808i during real-
time processing of data from LIGO Hanford Observatory (H1) and LIGO
Livingston Observatory (L1) at 2023-08-08 04:03:46.430 UTC (GPS time:
1375502644.430). The candidate was found by the CWB [1] analysis
pipeline.

S230808i is an event of interest because its false alarm rate, as
estimated by the online analysis, is 6.9e-11 Hz, or about one in 1e3
years. The event's properties can be found at this URL:

https://gracedb.ligo.org/superevents/S230808i

Two sky maps are available at this time and can be retrieved from the
GraceDB event page:
 * cwb.multiorder.fits,0, an initial localization generated by cWB
[1], distributed via GCN notice about 2 minutes after the candidate
event time.
 * cwb.multiorder.fits,1, an initial localization generated by cWB
[1], distributed via GCN notice about 7 minutes after the candidate
event time.

The preferred sky map at this time is cwb.multiorder.fits,1. For the
cwb.multiorder.fits,1 sky map, the 90% credible region is 7195 deg2.

For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide
https://emfollow.docs.ligo.org/userguide/.

 [1] Klimenko et al. PRD 93, 042004 (2016)