Viewing posts from August, 2009

Telescope Graphs and Statistics: New Webpage Addition

New addition to the website:

Student success with asteroid project

I have been working with a student from Mechelen Technical School (near Antwerp), Belgium on an asteroid project. The student contacted me about using the "Making Craters " activity as part of year long project for final year of secondary school. He has just submitted his dissertation and has presented it to a judging panel. Here are his experiences

Why we call the Haleakala site OGG

It is company policy to name each of our sites (internationally) after the closest airport, using the 3-digit airport code. Santa Barbara is SBA, which is quite understandable. Haleakala is labelled OGG after Kahului airport on Maui. The origin of this acronym is slightly mystifying, and the reason for it is as follows.

Last day on Haleakala

Last night, we realised that all the analysis we did on the polar alignment and azimuth axis the night previously had been the wrong way.  We were so frustrated!  I would like to blame altitude for this, but it appears to be a software issue which told us to move the back end of the telescope up, when in reality we had to go down.  This confused us for around an hour but we soon got back to the taking of pretty pictures. Here are some examples of the exposures we did.  These observations were taken during a full Moon (you can see the glow of Moonlight in the corner of some of these images, particularly in NGC 253) and we haven't made any calibration images yet; so we will be getting even more spectacular images in the future.

First light

After 15 hours on the mountain, we got first light on the South 0.4m.   The first images looked a little strange (see the bottom image) because the telescope wasn't focussed yet.  Once this was done, we checked the drift on the stars and saw they were moving south on the images. To fix this, Jacob and Wayne moved the azimuth axis (by around 0.75 inches) and the drift was significantly improved.  We then checked the polar alignment of the telescope by moving between a bright star at the zenith (i.e. with the telescope pointing straight up, and this was our reference star which we made sure lined up in the centre) and two other stars.  One star at -2h away in right ascension (RA) (due East) and the other +2h in RA (due West).  The stars were offset from the centre and by interpreting the pattern, we could deduce that the telescope was overshooting the pole and wasn't correctly aligned.  We corrected for these using the computer link up to the telescope and after some extra focussing and collimation attempts (see the donut shaped stars in the second to bottom image), we called it a day (night) at about 2am in the morning; we needed to figure out a better drift/collimation and pointing model (since we were as good as we could get by eye) and that would require some brain cells.  Altitude is a funny thing, I won't mention the hour we spent searching for sources (even trying to find the Moon) before we realised we were 15 degrees off from where we thought we were pointing in RA.  We really shouldn't have been off by that much!  However, 15 degrees in RA is the equivalent to 1 hour - that gave us a big hint to what the problem was and yes the laptop we were using to control the telescope was 1 hour off local time..... I definitely blame the altitude.