GW170608

GW170608: two black holes merging about 340 Mpc away, localized to 392 square degrees at 90%.

Arrived

2017-06-08

What merged

two black holes

Distance

340 ± 130 Mpc

50% credible region

96.7 square degrees

90% credible region

392.2 square degrees

Nearly missed. Hanford was being worked on when it arrived — engineers were adjusting the mirror alignment — so only its data above thirty hertz could be trusted, and the detection rests on Livingston with a clipped record beside it. Two black holes of about eleven and eight solar masses, 340 Mpc away, the lightest pair of the run; and with two detectors, a region of 392 square degrees rather than a patch.

Those two areas are credible regions rather than a boundary: the smaller holds half the probability and the larger nine tenths, and the tenth left over really is outside it. There is no right ascension and declination here because there is none to give — open it in the app to see the patch itself.

GWTC-1 sky localization for GW170608 — LIGO Scientific Collaboration and Virgo Collaboration

Open it in Bhagol — opens the app if you have it, and this page if you do not.