It has been a couple of decades since I observed in below freezing weather. Last night was awesome. I collimated the optics in late afternoon, and had very nearly perfect star images: very close to perfect round dots. I still do not have tracking perfect because getting true north is hard.
M42 was breathtaking, especially at 156x.
Losmandy mounts have vernier controls for moving the polar axis fractions of a degree, and one of mine has a polar alignment scope in the axis as well. On an equatorial platform you are trying to get the axis, which is effectively parallel to the ground, punted at the North Star. In retrospect, putting the platform on a lazy Susan to allow that sort of vernier adjustment would have been a good idea. Trying to make fine adjustments by moving a platform that weighs 130 pounds or so is not easy.
I also made one great improvement, though. The other night when trying to move or back in, I grabbed the telescope by the rocket box and tried to drag it that way, but inevitably I ended up losing it slightly which moved the entire assembly up enough to pull the top part of the platform of the base. This involved holding everything up until my wife returned to help list it off and reinstall it. So I drilled a couple 1" holes in the edge of the wooden platform that interfaces the casters and the equatorial platform, and tied a rope through both holes. Now I can pull the entire assembly from below, which prevents upward motion on the equatorial platorm. Even with my still somewhat rough surface. It moves easily and smoothly.
Define freezing. I used to think of temperatures just at 32 or under by a couple of degrees. Right now its 28 degrees iN DFW and we are having hail (not clear skies). And its been down to 14 this winter.
ReplyDelete32 and below seems to cross the line from warm parka to go inside.
ReplyDeleteThe coldest nights are those with the least amount of moisture in the atmospheric column - lowest greenhouse effect. That may help with the clear images.
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