Finally! This is very exciting: The Hubble has captured what is known as a Kilonova and in the process helps us down the road of showing a short-duration gamma-ray bursts can be set off by the collision and merger of two of the densest objects we know of: a pair of neutron stars or a neutron star and a black hole.
The gamma-ray burst occured in the constellation Leo at a distance of 4-BILLION light-years.
I’ll let NASA explain (the link goes to a more detailed explanation plus more images):
NASA’s Hubble Space Telescope recently provided the strongest evidence yet that short-duration gamma ray bursts are produced by the merger of two small, super-dense stellar objects.