Digital Chum - Virtual fish guts and other nonsense


Cool on a Galactic Level

The Arches ClusterWhile perusing Tom’s Astronomy Blog, I saw a post about the Arches Cluster, which is near the center of our galaxy, a mere 25,000 light years away. Pictures of space always fascinate me, but this picture comes with information that takes “fascinate” to a whole new level.

The Arches Cluster is a small (relatively speaking), dense cluster of huge baby stars. The new picture from the European Organization for Astronomical Research‘s Very Large Telescope is “one of the sharpest views ever of the Arches Cluster.” Check out the press release to see more details of the photo of this area of our galaxy. It’s breathtaking.

From the press release:

“With the extreme conditions in the Arches Cluster, one might indeed imagine that stars won’t form in the same way as in our quiet solar neighbourhood,” says Pablo Espinoza, the lead author of the paper reporting the new results.”However, our new observations showed that the masses of stars in this cluster actually do follow the same universal law”.

In this image the astronomers could also study the brightest stars in the cluster. “The most massive star we found has a mass of about 120 times that of the Sun,” says co-author Fernando Selman. “We conclude from this that if stars more massive than 130 solar masses exist, they must live for less than 2.5 million years and end their lives without exploding as supernovae, as massive stars usually do.”

For reference, the most massive known star is the Pistol Star, with a mass of about 200 times that of our sun. That’s in our galaxy. The biggest known star in diameter is VY Canis Majoris with a solar radius of about 18,000 – 21,000 (that’s 18 – 21 thousand times bigger than our sun). It’s also in our galaxy. Outside our galaxy, we can see other galaxies, but not much of their contents… at least not directly.

Seeing those stars in the Arches Cluster is fascinating for me, but for an astronomer, it’s got to be the stuff of dreams. There are lots of stars to study, but this formation is unique.

Our galaxy (the Milky Way, for those of you who haven’t kept up) contains an estimated 200 to 400 billion stars. The observable universe probably contains more than 100 billion galaxies.

That’s a lot of stars.