LIGO Virgo GW170814 Skymap
Credit & Copyright: LIGO-
Virgo Collaboration -
Optical Sky Data: A. Mellinger
Explanation:
From around planet Earth
three gravitational wave detectors
have now reported a joint detection of ripples in spacetime,
the fourth announced detection of a binary black hole merger in the
distant Universe.
The event
was recorded on 2017 August 14, and so christened GW170814,
by the LIGO
observatory sites in Hanford, Washington and Livingston, Louisiana,
and the more recently operational Virgo Observatory near Pisa, Italy.
The signal was emitted in the final moments of the
coalescence of two
black holes of 31 and 25
solar masses located about 1.8 billion light-years away.
But comparing
the timing of the
gravitational wave detections at all
three sites allowed astronomers to vastly improve the location
of the signal's origin on the sky.
Just above the Magellanic clouds and generally toward the
constellation Eridanus, the only sky region consistent
with signals in all three detectors is indicated by
the yellow contour line in this all-sky map.
The all-sky projection includes the arc of our
Milky Way Galaxy.
An improved three-detector location of the
gravitational
wave source allowed rapid follow-up observations by other,
more conventional, electromagnetic wave observatories that
can search for potentially related signals.
The addition of the Virgo detector also allowed
the gravitational wave polarization to be measured,
a property that further confirms
predictions
of Einstein's general relativity.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
