Looking Up: Diamonds Off The Sole Of His Shoe

Nov 21, 2016

M35, pictured above on the upper left. An older and more compact open cluster, NGC 2158, is visible above on the lower right.
Credit Credit & Copyright: Canada-France-Hawaii Telescope, J.-C. Cuillandre (CFHT), Coelum / NASA

This week on Looking Up we learn about yet another object Charles Messier looked down on - the open star cluster, M35.  

Do you like to look at babies? What about really pretty babies? What about really pretty babies that are only hundred million years old? Well, have I got a star cluster for you – Messier object number 35. And you can find it in southern Colorado skies right now, a little bit to the east of the left foot of the right-hand twin in the constellation Gemini.

So what is M 35? It is what astronomers call an open star cluster. Stars usually form out of almost unimaginably vast clouds of gases, made up of a wide array of chemical elements. Over the eons, gravity creates globs of matter within these clouds that slowly pull more and more material onto them, to the point that they become big enough to squeeze their cores hard enough to ignite nuclear fusion. And a star is born.

Or, more correctly, a lot of stars are born. Because in these clouds of gas we often see hundreds of new stars, all roughly the same age. Some gas clouds, like the famous Orion nebula, contain baby stars and regions where the gases continue to condense, which will form new stars in the future. Perhaps we could call these gas clouds “pregnant nebula?” Well, maybe not.

But there are other areas, such as M 35, that are just old enough that the gas has largely collapsed into the stars, leaving behind a region with lots of bright baby stars, and not too much gas. These open clusters are the infants of the universe, and over the coming billions of years, the individual stars will slowly drift apart, and mix in with the other stars in our Milky Way galaxy, slowly revolving around the galactic core every 250 million years or so. But while they are still close together, these open clusters make up one of the most beautiful objects in the sky – a collection of bright diamonds gleaming in even a relatively small telescope’s eyepiece. A telescope may pull in up to 120 of the baby stars, but astronomers believe that M 35 contains more than 500 newborns. Let’s hope they’re not all teething at once.

If you’d like to take a closer look at M 35, or any of the other wonderful and amazing things in the sky, please visit CSASTRO.org for a link to information on our monthly meetings and our free public star parties! 

This is Hal Bidlack for the Colorado Springs Astronomical Society, telling you to keep looking up, Southern Colorado!