Time–frequency representations (Chatterji et al. 2004) of data containing GW190814, observed by LIGO Hanford (top), LIGO Livingston (middle), and Virgo (bottom). Times are shown relative to 2019 August 14, 21:10:39 UTC. Each detector's data are whitened by their respective noise amplitude spectral density and a Q-transform is calculated. The colorbar displays the normalized energy reported by the Q-transform at each frequency. These plots are not used in our detection procedure and are for visualization purposes only.
GW 190814 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 14 August 2019 at 21:10:39 UTC,[2] and having a signal-to-noise ratio of 25 in the three-detector network.[1] The signal was associated with the astronomical super event S190814bv, located 790 million light years away, in location area 18.5 deg2[n 1][1][3][4] towards Cetus or Sculptor.[5][6][7][8][9][10] No optical counterpart was discovered despite an extensive search of the probability region.[11]
Discovery
In June 2020, astronomers reported details of a compact binary merging, in the "mass gap" of cosmic collisions, of a first-ever 2.50–2.67 M☉ "mystery object", either an extremely heavy neutron star (that was theorized not to exist) or a too-light black hole, with a 22.2–24.3 M☉ black hole, that was detected as the gravitational wave GW190814.[1][12]
"We don't know if this object is the heaviest known neutron star or the lightest known black hole, but either way it breaks a record."
The mass of the lighter component is estimated to be 2.6 times the mass of the Sun (M☉ ≈ 1.9891×1030 kg), placing it in the aforementioned mass gap between neutron stars and black holes.[1][13][14][15][16][17]
Despite an intensive search, no optical counterpart to the gravitational wave was observed. The lack of emitted light could be consistent with either a situation in which a black hole entirely consumed a neutron star or the merger of two black holes.[14]
^Ackley, K.; et al. (5 February 2020). "Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger S190814bv". arXiv:2002.01950v1 [astro-ph.SR].