Observation of Gravitational Waves from the Coalescence of a $2.5\text{-}4.5M_{\odot }$ Compact Object and a Neutron Star

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration +1793

We report the observation of a coalescing compact binary with component masses $2.5\text{-}4.5M_{\odot }$ and $1.2\text{-}2.0M_{\odot }$ (all measurements quoted at the 90% credible le…