Astronomy: Fall Treats - The Pleiades

Spacers Astronomy

With the end of the calendar year comes autumn and winter in the Northern hemisphere. The nights close in to give us longer star gazing time, but this also means the Sun isn't in the sky long enough to heat the land and air. It's cold and it's dark, and you can see your own breath - it's perfect for looking at the stars!

One of the best and easiest objects for winter viewing is the Pleiades open star cluster in Taurus. With the naked eye, the Pleiades will appear as a small "smudge" of light that beckons you to look closer, and you don't even need a telescope to do so - this is a cluster that looks good even with a modest pair of binoculars. Some astronomers even say that they prefer to view the Pleiades through binoculars as the cluster covers a wide field of view, and its beauty as a whole is more striking than resolving the individual stars it contains.

The Pleiades is easy to locate in the winter sky

Known as M45 - Messier's 45th catalog entry, the cluster is often referred to as the Seven Sisters, coined from the names given to the 9 prominent objects in the cluster. Looking at the brightest stars in the image below (Click to enlarge), to the left we can see the parents, Plione atop Atlas. As we scan right we see their children, the sisters. Alcyone, Maia, Electra, and Merope form the roughly square shape in the middle. To their right we see Caleano, moving up to Taygeta, and then finally up and left to the twin stars known as Asterope. A steady hand and well focused binoculars will make resolving, or "splitting" Asterope worth the cold hands.

The Pleiades Open Star Cluster

There are over a thousand other stars in the cluster, but the bright central group is by far the most stunning feature, made all the more bright by the starlight reflecting off the gas from a nebula the stars are passing through, Beginning life as the babies of a stellar nursery, the stars have all since blown away the gas from the nebula they formed from, and at less than 100 million years old they are so bright because they are burning through their fuel supply very fast. They will shine brightly for now, but their beauty will fade in a few million years as they start to burn out.

Spitzer Space Telescope view of the Pleiades

A mere 440 light years away, the Pleiades is one of the closest open clusters to our solar system, but with modern levels of light pollution it has become a challenge to resolve its finer details in built up areas and cities. The beauty of a clear sky has faded with the unfettered growth of poorly designed street lighting. The once awe inspiring sights like the Pleiades and the Milky Way are all but lost on modern societies, but it really doesn't take that much to help with efforts to return to skies that once truly made us humble.

So, what can I do to help make my skies dark again?
All it takes is a voice of support, and every new voice will add to the volume so it can be heard. Spacers supports efforts to reduce light pollution. Please visit the International Dark-Sky Association at http://www.darksky.org/

Happy Viewing Spacers!

Images credit: Dumbbell, Bob Star, and NASA
Digg this


Anonymous said...

Amiable fill someone in on and this fill someone in on helped me alot in my college assignement. Gratefulness you seeking your information.