Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 26734

LIGO/Virgo S200114f: Identification of a GW unmodeled transient candidate
2020-01-14T03:24:22Z (4 years ago)
Deep Chatterjee at University of Wisconsin, Milwaukee <>
The LIGO Scientific Collaboration and the Virgo Collaboration report:

We identified the unmodeled transient candidate S200114f during real-
time processing of data from LIGO Hanford Observatory (H1), LIGO
Livingston Observatory (L1), and Virgo Observatory (V1) at 2020-01-14
02:08:18.239 UTC (GPS time: 1263002916.239). The candidate was found
by the CWB [1] analysis pipeline with a version of the search called
�IMBH�. This name is not a classification of the candidate.

S200114f is an event of interest because its false alarm rate, as
estimated by the online analysis, is 1.2e-09 Hz, or about one in 25
years. The event's properties can be found at this URL:

Two sky maps are available at this time and can be retrieved from the
GraceDB event page:
 * cWB.fits.gz,1, an initial localization generated by cWB,
distributed via GCN notice about 5 minutes after the candidate event
 * cWB.fits.gz,3 -- this is identical to cWB.fits.gz,1

The preferred sky map at this time is cWB.fits.gz,3. For the
cWB.fits.gz,3 sky map, the 90% credible region is 403 deg2.

For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide

 [1] Klimenko et al. PRD 93, 042004 (2016)
Looking for U.S. government information and services? Visit