Aligning My SCT

John Hansen

Well, Leon's article in July really hit home! I have gone through some crazy aligning antics in the past. Ever since I acquired my Celestron NexStar8i I found myself in "forever learning mode" and would take too much time attempting to get a perfect SCT alignment. After all - - I wanted a perfect alignment every time.

One thing I found, was I was always rereading the manual section on "Astronomy Basics" where there are five different methods of alignment described. Well, it took a while to learn how and when to use several of these methods. Let me go run through the alignment methods in the order I first learned and used them. Maybe this will be of some help to the first-timers.

The first method I learned was the Two Star Alignment method. Of course I needed a dark night where I could see two bright stars to choose from for the alignment to work (and the further apart the better).

I never got this method perfect, but I learned it worked better after I bought a compass and a bubble leveler. With these tools, I could more accurately level my tripod and I could properly point the telescope to Polaris in the northern sky. This allowed me to get an acceptable alignment with just minor centering adjustments on each of the two stars. Of course, when I auto slewed to another celestial object I found myself tweaking the alignment again.

The second method I learned was the Auto-Align method that required the input of necessary data to align the telescope. I quickly learned the Auto-Align method was only slightly easier.

First I entered the date, local time - either military or AM or PM, and if it was Standard or Daylight and the Time Zone. Next I entered the location coordinates, i.e. longitude and the latitude from where I was observing. Of course I first used the bubble leveler and the compass to position the telescope as in the Two Star method. With this completed the telescope automatically slewed to a bright star and I would then manually center align the star. Next the telescope slewed to a second star and again I would manually center it and if all was right the NexStar display would read "Alignment Successful". I quickly learned this method required to check first that no trees or obstructions blocked the view. I became an expert on the use of the "Undo" buttons.

The third alignment method I learned, and my favorite, is the Quick-Align method. With this method I entered the same info that the Auto-Align method required. The NexStar bypassed the slewing to two stars and simply modeled the sky based on the input data. I then selected a bright object using the computerized hand controller. The telescope would slew to the object. I found the moon works best if it visible. The "Quick" part I liked was if the moon was not exactly centered, I would just move the tripod legs slightly to get the moon centered. The moon and planets could then be tracked in altazimuth in any part of the sky.

The best part about using the Quick Align is that you don't need a dark sky if the moon is out. At last falls Antioch Library Star Party I set my telescope up in the afternoon when only the moon was visible. I did the alignment and auto slewed to Jupiter and it was right on even though not visible with the naked eye at that time. And when the first observers looked through the telescope at Jupiter and then looked at the sky all were mystified that they could not see anything in the blue sky.

Some tips I learned. With any of these alignment methods I made sure that the red dot on my Star Pointer Finderscope was centered as soon as I got my telescope center aligned on an object. I also found that Vibration Suppression Pads worked well, particularly if there are windy conditions.

Published in the February 2009 issue of the NightTimes