Field Journal from Trisha Borgman - 3/4/96

PROCESSING DATA AND A CHANCE TO GO TO ARIZONA

I have exciting news! I will be going on an observing run in March! The GSPC-II team (do you remember what that stands for? Guide Star Photometric Catalog II...the "phone book" of the stars) has an observing run at the Kitt Peak telescope (near Tucson, Arizona) in late March, and I will be going along! There will be two of us on the run: the chief observer and myself. I'm really excited about it!! I've never been on a run before, so this will be an amazing opportunity! I will be sure to tell you all about it!!

Last time I wrote, I talked about how I have to run the data which comes back from the telescope through many steps of data reduction in order to remove the "signature" of the telescope itself. That is all done now. But my role in preparing the data for the actual catalog isn't nearly finished! After the data has been cleaned up, I have to run it through a whole sequence of photometry reductions. Photometry is essentially measuring the amount and color of the light which comes from a star. This is what we're interested in (that's why our catalog is called the Guide Star PHOTOMETRIC Catalog).

So what do I do? Well, once again it involves many computer programs. In fact, an entire software system was developed by my boss in order to make this process run more smoothly. I am not much of a programmer myself, but I have learned how to use all of these programs. There are many steps involved, but as I said, the end result is to measure how much light is coming from the stars we're measuring, and what color the light is. The color tells us so much about how the star really works: how much energy the star generates, how old the star is, and how far away it is. All the stars we are studying are from our own Milky Way Galaxy; in fact, when you look up at the night sky, all of the stars you can see are within the Milky Way.

One of the most important steps I am responsible for is actually identifying the stars we want to catalog. The first version of the GSPC catalog was released in 1988 (I was in 8th grade then!), and I use the star charts from that version in order to identify the correct stars for the new version. This was very difficult to get used to at first. When I look at a CCD frame, I know pointed, but I still have to identify which star is which! So, I look very carefully at the star chart and compare the patterns in the chart to the patterns in my image. From there I can usually identify which star is needed. At first, I had to ask my boss for a lot of help with this part of my work--especially when there were hundreds of stars in a single image, it was so hard for my eyes to get used to locating a single star! Now that I have more experience, though, it's pretty easy--it just took time, patience, and practice!

In my biography statement, I said that I also tutor an inner-city elementary school child. I met her for the first time about a week ago--she's a 6 year-old girl named Latarsha, and we're having a lot of fun together. It's an amazing challenge to try to teach someone how to read, or how to understand addition. I see her twice a week, on Mondays and Wednesdays, for about 2 hours each time. It's a great study break, and I really enjoy doing something to help people.

Look at the time!! Well, it's time for me to meet Latarsha! Have a great week, everybody!!