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The interactive skymap shows the localizations of the various gravitational-wave detections in the sky and helps to understand the importance of multimessenger astronomy.
Using the skymap
Click on the various options below to display information relating to each detection.
About the detections
#5. GW170817: sky localizations of the "golden binary"
On the 17th of August 2017, astronomers around the world were alerted to gravitational waves observed by the Advanced LIGO and Advanced Virgo detectors. This gravitational wave event, now known as GW170817, appeared to be the result of the merger of two neutron stars (BNS). Less than two seconds after the GW170817 signal, NASA's Fermi satellite observed a gamma-ray burst, now known as GRB170817A, and within minutes of these initial detections telescopes around the world began an extensive observing campaign. The Swope telescope in Chile was the first to report a bright optical source (SSS17a) in the galaxy NGC 4993. This observation firmly connects kilonovae with the BNS merger, providing evidence that kilonovae result from the radioactive decay of the heavy elements formed by neutron capture during a BNS merger - including gold and platinum - solving a decades long mystery of where about half of all elements heavier than iron are produced. GW170817 marks a new era of multi-messenger astronomy, where the same event is observed by both gravitational waves and electromagnetic waves.
#4. GW170814: a gravitational-wave signal emitted by a binary black hole system localized in the narrowest sky area reconstructed to date
GW170814 is the fourth published detection of gravitational waves. As was the case with the first three published detections,
the waves were generated by the coalescence of a pair of stellar-mass black holes. When we compare its position reconstruction in
the Universe with the previous events, the sky localization of GW170814 is the narrowest.
This new and exciting result was reached through a triple-coincident detection, coordinated by a body of more than 1,000
international scientists forming the LIGO and Virgo Collaboration (LVC).
#3. GW170104: third detection of Gravitational Waves emitted by another binary black hole system
As was the case with the first two detections, the waves were generated when two black holes merged to form a larger black hole.
The new-found black hole, located about 3 billion light-years away (twice as far away as the two previously discovered systems) has a mass of about 49 times that of our Sun, an intermediate value between those previously detected in 2015 (62 and 21 solar masses for the first and second detection, respectively).
#2. GW151226: the second detection
As with the first event, GW150914, this one was consistent with the merger of two black holes. However, in this event the black-hole
masses are slightly smaller - 14 and 8 solar masses - producing a more massive black hole of 21 solar masses.
This means that during the merger, which occurred approximately 1.4 billion years ago, mass roughly equivalent to the Sun was converted
into gravitational waves. The signal comes from the last 27 orbits of the black holes before they merged. The signal arrived in the Livingston
detector about 1.1 milliseconds before reaching the Hanford detector: in this way the position of the source was roughly determined.
#1. GW150914: the first detection of gravitational waves - two merging black holes
On the 11th of February 2016, the LIGO-Virgo Collaboration announced two great discoveries: the first detection of gravitational waves and the first detection of a binary black hole merger.
This catastrophic event, producing the gravitational-wave signal called GW150914, took place in a distant galaxy more than one billion light years from the Earth. It was observed on the 14th of
September 2015, by the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO). The peak gravitational-wave power radiated during the final moments of the black hole merger was more
than ten times greater than the combined light power from all the stars and galaxies in the observable Universe.
This remarkable discovery marked the beginning of an exciting and entirely new era of astronomy
as gravitational-wave window on the Universe was opened.