- If things go wrong, the first thing you can try is calling Francisco. If it's late, just close up the dome and send an email to Francisco with details. Shut down as well as possible.

- If dome won't close, cover telescope and computers with plastic. (Number for PPD?)

Some common problems (with some suggested solutions):

Due to the German-equatorial mount-style of the telescope, when it reaches zenith it can no longer track your object across the sky. Solution: transit the telescope.

If it gets too cold (< 40° F) the dome may start slipping. Solution: close the dome up best you can, and stop observing for the night.

Over the course of the night the RH will skyrocket (because it gets colder). The mirror will usually fog up. Solution: Close dome, turn up AC. Hairdryer?

In some fields it’s incredibly difficult to find a star to track on, because they’re far from the MW and there just aren’t many stars there. Solution: Check the finder chart with the template. Maybe you want to wait until it crosses the meridian (if that’s an option). Take many shorter images (< 40 s).
If you take flats before the CCD cools off you will notice an odd ring around the edge of the images (see above image). The center of the CCD cools down quicker than the edges, and apparently the sensor is located at the center. Solution: Wait a little longer to take the flats.

The list of alignment stars is not extensive (yet). You may not have a good star to align on. Solution: Add a new bright star to the list and increase the counter on the top of the document by 1.


The above image shows two problems: the image is out of focus (doughnut shapes) and we can see the comatic aberration (the “comet” tails or cone shape of the stars). The aberration is much clearer than normal since the image is out of focus. Solution: Focus the telescope and try to use the middle portion of the CCD. The center of the CCD is also subject to less vignetting, so it’s a better place to have your target in general.


The above image shows vignetting on a raw image. This is also quite a long exposure (~10 minutes), so you can see that the very bright stars are bleeding and there are a number of bright pixels caused by cosmic rays.