- Eta Cas is a double star within our own Milky Way galaxy. It is quite close to Earth, at just 19.4 light years, so the photons reaching your eye from the star tonight are under 20 years old. What makes Eta Cassiopeiae so interesting is that the primary star is a G-class star much like our Sun. Our Sun would look similar from Eta Cas if we were peering back it it from there. It also has 97% of the mass, and is 101% of the radius of our Sun. It is much like a twin of our host star in many respects, though it is likely about a billion years older. Here is how to locate it.
- Coma Star Cluster (Wikipedia)
The Coma Star Cluster (also known as Melotte 111 or Collinder 256) is a small but nearby open cluster located in the constellation Coma Berenices. The cluster contains about 40 brighter stars (between magnitudes 5 and 10) with a common proper motion. The brighter stars of the cluster make out a distinctive “V” shape as seen when Coma Berenices is rising. The cluster used to represent the tail of Leo. However, in around 240 BC, Ptolemy III renamed it for the Egyptian queen Berenice’s legendary sacrifice of her hair.