My First Night at CTIO

Thursday, April 6th, 2006 at 03:33 AM by Administrator

Well, my “night” started around 3:00 pm with my collaborator, Dr. Roberta Humphreys (U Minnesota), and I learning the ropes of running the Yale 1-m telescope. The first thing we learned is don’t trust the manuals that are online, since “tweaks” to those procedures seem to be par for the course. By 3:30 we were taking “dome flats” and learning about opening up and shutting down for the night. Running the telescope requires somewhat simultaneous monitoring of 4 seperate computers that talk to one another:

• Yale4k: This computer is running Windows Xp is basically controls the camera. All images froming from the CCD camera in observtory upstairs are routed down to this computer first. The images, by the way, are 16 megapixels. We have shot over 240 of them thus far, and we have about 2 and a half hours to go yet.
• PC-TCS: This is the telescope control computer, if you want to point the telescope at a new object or focus the telescope, you have to use this telescope.
• PCGuider: This controls a really cool autoguider to keep the telescope pointed. Simply select a star on this computer and the telscope will stay centered in the field by tracking that star.
• Yale1m: This computer runs Prospero, the observing program. From Prospero, we decide how many exposures to shoot, their duration, and the filter we will see through. It talks to Yale4k to clean up the output from the camera. It also is where we display the raw images using IRAF.

So far, our only issues tonight have been

• Focusing the images has proven to be a bit tricky, especially since the bluest filter we are using has a different focus than the blue, visible, and red filters we are using.
• Seeing that is a bit worse than we expected (about 1.2 to 1.4 arcseconds at this telescope, although the CTIO sky conditions tracker here is reporting only 0.6 arcseconds). Larger seeing means it is harder to see the really faint stars we are hoping to see, especially in the bluest filter.

We can’t really evaluate the images we have gotten tonight yet (I will have a summer student working on that problem for 2 months this summer), but this has already been very educational for me, since the only extensive observing I have done before tonight has been at radio wavelengths.

We don’t have a lot of free time (I am writing this blog entry in little 2 minute bursts during exposures), the longest stretch we have without touching the keyboard is ten minutes when we perform a sequence of 6 images on a field (before needing to re-focus). However, I have taken advantage of those short free moments to step outside. Since about 12:30 am, when the moon set, the sky outside has been amazing. Extremely dark, and within 30 seconds my eyes are dark adapted enough to see the Milky Way stretching over head. The Galactic Center is about 20 degrees from overhead and it is amazing. It bulges compared to the rest of the Milky Way, clearly indicating the galaxy is “thicker” in that direction. I was also able to see the whole of Scorpius high overhead, its tail dipping into the center of the galaxy (which lies in the constellation Sagatarius). Finally, since Dr. Humphreys is an expert on the high mass star Eta Carina, she pointed it out to me along with the Coalsack (a dark nebula). Everything in the skies here is crystal clear, it is amazing. You can’t miss the Milky Way and its dust lanes… they jump out at you and demand your attention. Amazing. Too bad we are moving toward full moon next week, because it means dark skies like this are going to get rarer as the week moves forward.

PS: I spoke too soon about things going smoothly. We had the Yale1m computer crash out of its GUI … we lost about 30 minutes … drat.

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