Cassiopeia A
>
Cassiopeia A is a supernova remnant in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. Wikipedia
Declination: +58° 48.9′
Right ascension: 23h 23m 24s
Radius: 5 light years
Distance to Earth: 11,090 light years
Date: 1947
Remnant: Shell
Constellation: Cassiopeia