Astronomy Internship - Day 31

I ended up getting another 3 images finished today. That leaves me with 5 to go so I should be done Wednesday and ready to move onto the next step.

I also found out that I'm going to be working on another project here with NGC 7142. Instead of looking at the cluster in the standard UBV filter system, we're going to use data from the 2 Micron All Sky Survey (2MASS) and try to get a better understanding of the cluster.

The advantage in using the infrared is that it's less affected by the interstellar cloud lying in front of the cluster.

What we're primarily looking to do is fit this cluster's HR diagram with the theoretical one. The reddening caused by the interstellar cloud shifts things right because it makes objects appear redder. It also shifts things down because it makes things appear dimmer.

So we'll be trying to figure out how to properly move thigns back up and to the left on that diagram.

But with using the infrared, there's another problem we'll be facing. Since the majority of stars in the galaxy are low mass, red stars (as much as 90% of all stars are this), looking at things in the infrared will bring out a lot more. That's good for looking at the cluster, but since the cluster lies in Cepheus, which is near the plane of the milky way, it's a crowded star field, and thus, more stars are going to be popping out that aren't necessarily assosciated with the cluster and will contaminate the results.

My advisor and I are currently working on trying to figure out how to avoid this.

What we're really looking for is the location of the Red Giant Branch (RGB) which, as I'll explain in my next post on astronomical data and analysis, will be able to help us determine the age of the cluster.