"Taking Pictures of Galaxies"

Trisha Borgman - March 27, 1996

    Hmmm...we've got a problem! When we take pictures through the telescope, it's very important for the telescope to keep up with the rotation of the earth, otherwise the stars would streak across our images. Here in the console room, there is a small TV which is attached to a camera inside the telescope itself. This camera lets us see what the telescope sees. We then use something akin to video game buttons to move a targeting square on the TV screen to a bright star in the field. This enables the telescope to lock on to the bright star and keep up with its motion across the sky. That's where our problem is. I used the targeting square to lock on to a bright star (called a guide star) and I turned on the telescope tracking...but the guide star just drifts right out of the target square. And as a result, our first set of images are nothing but streaks! We called the observing technicians, and they just came to help us. After about 20 minutes, they determined that the mechanical components of the guiding circuitry had become loose. Apparently the tracking and guidance equipment is pretty old (older than me!), and it periodically becomes loose. Thankfully, the technicians were able to fix our problem very quickly!

So, we're guiding now...but unfortunately it's too cloudy for our observations! The sky is relatively clear, but the bright moonlight makes it clear that there are high cirrus clouds all around the sky. For many astronomers, cirrus clouds are OK-- obviously not ideal conditions, but still manageable. But since we're working on a photometric star catalog, the ice crystals in the cirrus clouds cause too much interference in the starlight. For us, cirrus clouds are just as bad as thunderstorms! We'll wait for half and hour or so, then check the sky again...

It's now 12:45am, and it's still too cloudy for our observations... however, I have some exciting news! I've spent the last 2 hours or so just taking pretty pictures of galaxies! As I said earlier, it's too cloudy for photometry, but not at all bad for just taking pictures! So, I loaded the Messier catalog into the telescope's guidance computer. The Messier catalog is a huge compilation of galaxies--it was created in the early part of this century by an astronomer named Charles Messier. In all honesty, I've just been exploring tonight! I searched the catalog for objects which are visible from this latitude and longitude at this time, and I just practiced pointing the telescope and taking exposures. I had no idea how to choose the correct exposure times, so I literally started with a 60-second exposure and just went by trial-and-error from then on! This has been tremendously fun for me! These galaxies are absolutely spectacular... I know it's bad news that the weather has been uncooperative for our photometry, but on the other hand this has given me an opportunity to do some searching on my own. I've learned so much about the practical aspects of observational astronomy tonight!! These images are GORGEOUS!!! I've done a little bit of data reduction on them, and they just look spectacular. It's been exciting to direct my own learning tonight--after all, I had no idea what most of these galaxies even looked like when I began... I think I'll take a few minutes to walk outside and just stargaze...

Let's hope for better weather tomorrow night--that's our last night up here!!!

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