Week 3: Cassiopeia

For Valentine's Day, since my roommate and I were both Valentine-less, we decided to watch a chick flick on Netflix to distract us from our own lonely lives. The film was actually pretty bad, but the constellation Cassiopeia featured briefly. I vaguely knew of the constellation beforehand (I think I got to see it this summer), but the movie piqued my interest (in part because I hadn't thought of anything else to write this post about).

As can be seen above, the constellation is composed of 5 stars in a W-shape. Supposedly this shape depicts the Aethiopian queen Cassiopeia, who was mother to Andromeda and was imprisoned in the sky for bragging that her daughter was more beautiful than the sea nymphs. I don't really see it, and honestly, I've never been sure how the Greeks came up with this stuff--I'm just going to assume it's because they didn't have much else to do besides philosophizing and stargazing back in those days. 

The four brightest stars that form the constellation range from about 50 to about 550 light years away from the Earth. Although it's obvious in hindsight, I hadn't considered that stars in a constellation could be much farther from each other than they are from us--I guess it can still be pretty easy to fall victim to the ancient idea that the sky is basically a giant sphere surrounding the Earth. The brightest of the stars, Alpha Cassiopeia, is over 600 times more luminous than the Sun and has a mass approximately 5 times that of the Sun. 

There are also several other objects located within the constellation. M52 and M103 are open clusters (small groups of clustered stars created from the same giant molecular cloud) that are located within Casseopeia. These are much farther than the stars in the constellation--both are over 5000 light years from the Earth. Finally, two supernovae have been observed in the region of Cassiopeia. One of these was even farther than the clusters--10,000 or so light years away. Thinking about the widely varying distances in just this one constellation makes me wonder what sort of crazy stories the Greeks could've come up with if Earth were in a different part of the Milky Way and had a completely different perspective. 

Sources

https://en.wikipedia.org/wiki/Cassiopeia_(constellation)

https://upload.wikimedia.org/wikipedia/commons/c/c1/CassiopeiaCC.jpg

https://en.wikipedia.org/wiki/Alpha_Cassiopeiae

https://en.wikipedia.org/wiki/Open_cluster