When and how was Cassiopeia discovered?

NGC 147 is another dwarf spheroidal galaxy in Cassiopeia, approximately 2.53 million light years distant. Like NGC 185, it is a satellite galaxy of the Andromeda Galaxy (Messier 31) and a member of the Local Group of galaxies. It was originally discovered by John Herschel in 1829. It has an apparent magnitude of 10.5. read more

NGC 457 is another open cluster in Cassiopeia, also called the E.T. Cluster, the Owl Cluster, and Caldwell 13. The cluster was discovered in 1787 by William Herschel. It has an overall magnitude of 6.4 and is approximately 10,000 light-years from Earth, lying in the Perseus arm of the Milky Way. read more

The cluster was discovered by the French astronomer Pierre Méchain in 1781. It was the last object Charles Messier entered into his catalogue. Cassiopeia A . Cassiopeia A is a supernova remnant. read more