Sunday, 13 March 2011

SXR208: Day 2

Day two of the residential, and the first full night scheduled.

Today we get to play with telescopes, and start getting into the rhythm of the course.

It's a bus at 4:30 to get us to the observatory at about 5:30, we then have a talk in the planetarium. Tonight's was about the software we would be using, Maxim DL and excel. How we would be taking bias, flats and dark frames to allow better processing of the science images that we would take later.
Bias frames are a dump of the CCD detector to sense the effect the bias voltage on the chip has, this can then be subtracted from the full images.
Dark frames are exposures taken for the same time as the science frames, but with the shutter closed. This allows an estimation of the thermal noise that would occur on the image, and again can be averaged across several frames and subtracted.
Finally flat frames are images taken on a lit white image (a big round target held up to the telescope lit with a lamp) that allowed for vignetting, dust and other oddities of the optics to be taken into account and subtracted.

We spent the first half of the night in the lab, occasionally looking outside at the clear skies. We did some Maxim and excel processing of data, and my partner for the night and I were both pretty computer literate, we zoomed through the tasks. We finished with over an hour to spare, and the course director suggested that as there was a telescope spare we could have a play with it. We got it all set up and ready to run, and focused on Saturn, when they had a breakdown in one of the other domes, and kicked us out! So close.
Midnight, and after our snack session and quite a lot of strong coffee, it was our legitimate time in the domes. However the sky had clouded over and nothing was visible now. So we went through the motions of setting up the telescope, taking darks, flats and biases, and then went through the shut down procedures for parking the telescope. Then after a bit more time in the lab, we went back to the bus at 4:00am for the ride back to the hotel. There we had to attract attention to get the main door open, and then to bed. Everyone had to remember to hang the "Do not disturb" signs on their door, as no one wanted their room cleaning whilst trying to sleep!

1 comment:

David H-T said...

That sounds familiar. And you have to turn the locks twice otherwise they don't lock. One of my week found this out to his cost two days in a row, when a maid walked in on him stark naked after a shower. I think he secretly liked it!