The LIGO Scientific Collaboration and the Virgo Collaboration report:
We identified the compact binary merger candidate S200105ae in data
from LIGO Livingston Observatory (L1) and Virgo Observatory (V1) at
2020-01-05 16:24:26.057 UTC (GPS time: 1262276684.057). The candidate
was found by the GstLAL  analysis pipeline. LIGO Hanford
Observatory (H1) was offline at the time.
The signal-to-noise ratio (SNR) was below threshold in V1 so the
candidate was treated as a single-instrument event. The false alarm
rate (FAR) estimated from the L1 trigger, 7.6e-07 Hz -- or about 24
per year -- was above the threshold we normally use for issuing a
public alert. However, after further offline analysis of the
candidate, we believe that its significance is greater than that
calculated in real-time processing. Follow-up observations may
therefore be justified.
The event's properties can be found at this URL:
We cannot quantify the probability of this event being astrophysical
at this time. However, if it is astrophysical, it is most consistent
with being a neutron star - black hole (NSBH) event. Under this
assumption, there is strong evidence for the lighter compact object
having a mass < 3 solar masses (HasNS: >99%). Using the masses
and spins inferred from the signal, it is possible but unlikely that the
merger left matter outside the final compact object. (HasRemnant was
estimated as 12% by the initial analysis, but this value is considered
One sky map is available at this time and can be retrieved from the
GraceDB event page:
* bayestar.fits.gz,0, an initial localization generated by BAYESTAR .
No GCN notice has been issued for this candidate.
For the bayestar.fits.gz sky map, the 90% credible region is 7719
deg2, dominated by the L1 antenna response. Marginalized over the
whole sky, the a posteriori luminosity distance estimate is 265 +/- 71
Mpc (a posteriori mean +/- standard deviation).
For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
 Messick et al. PRD 95, 042001 (2017)
 Singer & Price PRD 93, 024013 (2016)