Flat-fielding 101.

I have spent a good portion of the last few days trying to take telescope alignment data.The first night, we had network issues and weren't able to start until about 9PM. The process should start at 7, when the sky is still a bit bright, so that you can see the different mirrors of the telescope properly. This acts as your template. Once the sky gets dark, however, it makes it alot harder to get a good template. In prinicipal you can use the moon to light up the mirror facets, but the moon was too low the first night to do so. Last night, the weather was pretty bad, cloudy and such, so we didn't even bother setting up the alignment tool, and finally, tonight, I got lucky. We only managed to get a template image once it was fairly dark, but it should still be fine.

The way the alignment works is really interesting. You begin by pointing the telescope at a star. In prinicple, all the mirror facets should be lit up if you are at the focal point of the telescope and looking at the dish. However, some mirrors will be misaligned and they won't be lit up. If you move the telescope up, down, left or right with respect to the target star, eventually you can find a position so that a misaligned mirror facet will be lit up. Then, the angle difference between the star and your new pointing direction is related to the angle that the mirror is misaligned by simple geometry. 

A coworker of mine, Andrew McCann, who developed this method, has published a paper. The arXiv print can be found here. If anything, the figures are interesting.

I had to change dorms this morning. I have relocated to one of the sub-summits of Mount Hopkins, to the location of an automated telescope array called mEarth. I have the dorm to myself, which is both a blessing and a curse. It does get mighty creepy staying up on the Ridge at night, and the bed in the mEarth building is pretty tiny. 

mEarth has 8 16" telescopes. Note that this image is not my own; I pulled it from  rcopticalsystems.com

Back to work.

After a valiant effort by the day crew here, the VERITAS computer array is back online (mostly). This means that we (the observers) can start getting the array working again. I've been put in charge of getting one of the calibration systems (called the LED Flashers, I'll write about them later) up and running. Luckily, it's not time critical, I can do it at any time of the day, which makes life a lot easier. 

Hack'd

So, the VERITAS computer network was hacked at some point last week. Out of some 80 machines, we found 7 compromised machines, including our array controller box, and all of them have to be rebuilt from scratch. We are currently operating in a state where we can't even steer the telescopes (which means that for people like me who are not system engineers, there isn't much to do). 

So, Saturday another observer and I went to the Pima Air and Space Museum (a few photos have been attached) and then yesterday to the Pima County Desert Museum. Both the museums are really nice (even though the Desert Museum is essentially just some fenced in desert that you need to pay admission for) but they have some pretty cool animals. 

Most of the excitement started when we left the Desert Museum. In a nutshell, the catalytic converter on my car rusted through and detached the rear exhaust system from anything structurally sound. So, the entire muffler assembly was just holding itself on by the oxygen sensor and a set of bolts on the back. I managed to fix it with 2 coat hangers and some duck tape, but the car is crazy loud now and I need to replace the catalytic converter. It's a good thing that this didn't happen on (for example) one of the highways in the middle of Oklahoma. I didn't have a chance to take pictures (too dirty) but as soon as the ground dries I'm going to grab my camera so I can take pictures of my handiwork. 

Here are three videos that I've decided to post. Two of which are a bit old (one dating from when I was driving through New Mexico), but one from earlier today. Near the end of the third, there is a lightning strike in the field of view, then some crazy loud thunder. Unfortunately, neither of these effects came out well. 

Mirror swappage

Two days ago we began pulling mirrors off of Telescope 2 so that they could be replaced and recoated. It's a lengthy process where two people go up with boom lifts, take off a few mirrors at a time, and then bring them back down to the people waiting on the ground who package them up and then wait for the next batch. The pictures below are somewhat self explanatory.

"This picture doesn't encapsulate how bitch-ass hot it was outside." -Emmett 

Yesterday we put the mirrors back on ( a horrible job consisting entirely of 'hurry up and wait'). It's been really hot here, 35C and higher, so I'm pretty toasted right now, even by local standards.