NGC 4993

NGC 4993 is a lenticular galaxy located about 140 million light-years away in the constellation Hydra. It gained significant attention in 2017 when it became the site of the first observed collision of two neutron stars, an event known as GW170817. This collision produced both gravitational waves and electromagnetic radiation, marking the first time such an event was detected in both forms.

The galaxy itself has several concentric shells of stars and a large dust lane that stretches out into an "S" shape. These features are likely the result of a recent merger with another galaxy, which occurred about 400 million years ago. NGC 4993 also hosts a supermassive black hole at its center, with an estimated mass of roughly 80 to 100 million solar masses.

The neutron star merger in NGC 4993 created a kilonova, a powerful explosion that releases light equivalent to hundreds of millions of suns. This event provided valuable insights into the formation of heavy elements like gold and platinum, which are produced during such mergers.