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NGC 4993

galaxy in the constellation of Hydra

Key facts

Constellation: Hydra
Right ascension: 13 09 47.7
Declination: −23 ° 23 ′ 02 ″
Heliocentric radial velocity: 2916 km/s
Distance: 44.1 Mpc (144 Mly )
Group or cluster: NGC 4993 Group
Type: (R')SAB0^-(rs)
Size: ~55,000 ly (17 kpc ) (estimated)
Apparent size v: 1.3 x 1.1
Notable features: Host of neutron star merger detected as gravitational wave GW170817 and gamma-ray burst GRB 170817A

via Wikipedia infobox

Article

NGC 4993 starmap near ψ Hydrae, near galaxies of NGC 4968, NGC 4970, NGC 5042, IC 4180, IC 4197 NGC 4993 (also catalogued as NGC 4994 in the New General Catalogue) is a lenticular galaxy located about 140 million light-years away in the constellation Hydra. It was discovered on 26 March 1789 by William Herschel and is a member of the NGC 4993 Group.

NGC 4993 was the site of GW170817, a collision of two neutron stars, the first astronomical event detected in both electromagnetic and gravitational radiation, a discovery given the Breakthrough of the Year award for 2017 by the journal Science. The detection of gamma-ray burst GRB 170817A simultaneous with the gravitational wave event, for example, provided the first direct confirmation that binary neutron star collisions generate short gamma-ray bursts.