T - Point

Last night the waxing gibbous Moon was up and more than a few clouds were about as well but seeing that there were plenty of large gaps in the clouds I thought it would be a perfect night to get the new pointing model done using T - Point, when I arrived at the observatory I noticed that the computer was off and the temperature compensating focuser was flashing, I'm guessing that there was a power cut during the storm we had earlier on in the week, I booted up the computer and connected to both the telescope and camera without issue but when I tried to connect to the focuser it would not connect and came back with an error message from both Maxim DL and the Sky X, after ringing steve for help I switched the focuser back to manual mode and manually set the focuser back to the last known good focus, this worked well enough for me to be able to do the pointing model, the next issue was aligning the finder scope again which must have been knocked fairly far out of alignment at some point, this took me a while to get right but once I was happy that the finder scope and the field of view of the CCD were aligned again I got started on the pointing model, at first I had wanted to do an automatic calibration run but unfortunately the Sky X would not connect to the camera and I got error messages, I also noticed that it will be quite hard to keep up with an automated calibration due to the dome being fairly slow, not wanting to waste a good opportunity to get a pointing model done, I set about doing a manual pointing model using stars that I knew and that I could confirm through the finder scope, by the time the clouds really rolled in at 2:30 am, I had captured 57 samples, one problem I noticed when I was capturing the samples was that I couldn't take any samples from around Carina and Crux any attempt to jog the telescope in this area of the sky caused the mount to become confused and try to point the telescope at the floor, each time this happened I had to re-home the telescope before it would accurately point and track again.

The new pointing model confirmed that the altitude of the mount is correct but that the azimuth still needed to be adjusted ( by about 3 arc minutes ), I then enabled the Pro Track so that the new pointing model can make minor adjustments to improve the sidereal tracking rate of the Paramount GT - 1100S, at this stage the clouds had become so thick that trying to test the new pointing model's accuracy was pointless, so at 3:30 am I closed up the dome and called it a night, I'm looking forward to the next clear night when we can test out the adjusted tracking rate and also the accuracy of the new pointing model.

Posted by Jonathan Green