The LIGO/Virgo collaboration has just announced their detection of
a gravitational-wave signal, GW190814 (observed on 2019 August 14),
interpreted as the coalescence of a 23 solar-mass black hole and a 2.6
solar-mass compact object (which might be either a low-mass black hole
or a high-mass neutron star). No electromagnetic counterpart was (yet)
detected. The data have an overall signal-to-noise ratio of 25:1, and
are fully consistent with general relativity, modelling either a
binary-black-hole or a black-hole/neutron-star system at a (luminosity)
distance of about 240 Mpc.

The detailed paper is open-access at /Astrophysical Journal Letters/,
https://doi.org/10.3847/2041-8213/ab960f

Enjoy,
--
-- "Jonathan Thornburg [remove -animal to reply]"
Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
currently on the west coast of Canada
"There was of course no way of knowing whether you were being watched
at any given moment. How often, or on what system, the Thought Police
plugged in on any individual wire was guesswork. It was even conceivable
that they watched everybody all the time." -- George Orwell, "1984"