Cetus

When many think of astronomy, constellations are the fist thing that come to mind. They are something that any person can see, and with the right prompting, see the specific image that they are named for. There are many that say constellations tell a story of some sort. That may be true, but each constellation on their own tells a story. To each of these stories, there are three parts: that which is the scientific, the historic implications, and the story behind the name.

Take the Cetus constellation, for example. To begin with, the constellation itself is steeped in scientific significance. Not only is it one of the oldest known constellations, its recordings dating back to before our technology of telescopes, but within it are a variety of celestial objects that other constellations do not have. For one, the constellation contains the galaxy Messier 77 (NGC 1068), the 9th brightest spiral galaxy that we know of.

Cetus contains Mira, the first variable star to be discovered. Mira, over 332 days, changes in magnitude from a 2.0m (easily seen to the naked eye) to 10.1m (barely scene on a telescope) and back. This is where the part of the story dealing with historic implications comes in. The man who discovered Mira and her variability in 1596 was David Fabricius. Fabricius realized that this was not an ordinary star in the fact that it was moving on its own accord. This went against the previous believed Ptolemaic model of the heavens, that all centered around the earth. This discovery was one more push for the Copernican Revolution, the shift away from Ptolemaic’s model.

While it may seem that the discovery of this “shifting star” was well beyond the technology of astronomy and ability to notice such, it really comes as no surprise that the Mira was noticed in the 1500s. After all, the constellation Cetus itself had been known for centuries before that! Cetus, which is Latin for sea-monster or huge fish, was documented as early as the time of the Mesopotamians. They identified the constellation with Tiamat, the sea-monster. The Arabs also called the constellation a “leviathan like monster.” While the ancient Greeks also noted the constellation, they felt that it represented the gates of the underworld and the beginning on the Herakulean tales.

This northern winter sky dweller is hard to notice without focusing, as its size takes up nearly the entirety of the sky in which it’s in. While it’s surrounded by its watery neighbors of Picies, Aquarius, and Eridanus, it’s possible to over look this “gentle giant,” as the name Cetus lends itself to. Whether you remember the constellation for its scientific implications, the multiple connotations with the name, or even just the fact that it is a constellation at all, it’s important to keep in mind that each constellation lends itself to helping tell the tale of our solar system and those beyond.