Drifting
Observing notes from the evening of Friday, March 12, 1999
Hell must have surely frozen over on this night. It was an official Raleigh Astronomy Club observing night and it was clear! The club observatory was up and running but a few others and myself decided to go to the Big Woods site at Lake Jordan, NC, instead. For me, the Big Woods site offered better horizons and a shorter drive. I brought along my 8" Schmidt-Cassegrain telescope. I also did not keep notes during this session. I left that up to Michael King, who had his 8" LX200 Schmidt-Cassegrain which was controlled via a laptop computer.
It felt good being out and under the stars. Although I did happen to see a lot of objects, I really wasn't driven to do detailed observations. I just enjoyed being out there. The wife and kids were out of town which meant I had no curfew. I could stay out as long as I liked. It was very relaxing. I assembled my telescope and casually looked at a few objects. I'll provide a list below.
My main accomplishment was polar aligning my telescope using the "drift" method. I have a couple of different directions printed out in my notebook. I've read through them several times and thought I understood how it worked. But, the first time I tried to actually do the drift method (some time back), I got confused about a variety of things, such as the direction of drift, which way to move the scope, etc. Since I really didn't have an observing agenda, I decided that I would dedicate this night to figuring out how to do the drift method of polar alignment.
One problem that I had made too hard in the past was in selecting the star to watch for drift. I would look into the sky, trying to figure out exactly where the celestial equator was and then trying to find a bright star just the right amount of distance above it. The simple solution is to point the telescope toward the south, set the declination a few degrees in the positive, and just look through the eyepiece. You will see tons of stars. You don't need a bright star, you only need one that you can see. After going over the directions in my head a few times I finally figured out which way to adjust my mount according to which way the star drifted.
The next problem I was trying to make too hard was in selecting a star above the eastern horizon. Again I was trying to figure out exactly where east was. All I had to do was rotate my scope in right ascension and not worry with the declination. I actually had to use the western horizon because of trees and light pollution. I just rotated the scope as close to the horizon as I could get and picked a star in the eyepiece. I had to reverse my adjustments since I was using a western star instead of an eastern star, but that was simple.
In the end, I had my telescope aligned pretty well. I put a star in the crosshairs of my guiding eyepiece and it stayed there. I put Michael's camera on top of my scope and did a few unguided piggyback shots. I haven't seen the results yet, but I've got high hopes. Now that I understand the drift method of polar alignment, I'm not as intimidated by it as I have been in the past. It is a little time consuming, but once you understand it, you'll realized it is quite simple. During times I was waiting to see if the star drifted, I would wander around and look through the various other scopes at this gathering.
Here's a list of the objects we observed:
M42, the Orion nebula.
M1, the Crab nebula in Taurus.
Hind's Crimson Star in Lepus. This was pretty neat. It is the most red star I think I have ever seen. Nice deep color.
M95, M96, and M105, galaxies in Leo.
NGC3384, galaxy in Leo
M65, M66, and NGC3628, galaxies in Leo.
M98, galaxy in Coma Berenices.
NGC4216, thin, elongated galaxy in Virgo.
M99, galaxy in Coma Berenices.
M100, galaxy in Coma Berenices. There was a pinpoint of light near the center. I don't think there is a foreground star so it was probably just a bright nucleus.
NGC4450, galaxy in Coma Berenices.
M85, galaxy in Coma Berenices.
M84, M86, and NGC4438, galaxies in Virgo.
NGC2244, the Rosette nebula. The open cluster is large and bright. We could just see the boundaries of the nebulosity with an UHC filter. It was way too large to fit in the field of view of the eyepiece.
NGC2252, open cluster in Monoceros.
M5, a wonderful globular cluster in Serpens.
M3, another wonderful globular cluster, this time in Canes Venatici.
M51, the Whirlpool galaxy in Monoceros. Could just make out a hint of the spiral. Both components easy to see.
M53, globular cluster in Coma Berenices.
M13, king of the northern globular clusters in Hercules. Although it is huge and easily resolved, it was still too low in the murk and light pollution dome to offer any great views.
M44, open cluster known as the Beehive in Cancer.
NGC3344, small galaxy in Leo Minor.
NGC3486, galaxy in Leo Minor.
NGC2683, galaxy in Lynx.
We also took a look at Mars once it got above the trees. The sky was not too steady so we didn't expect to see much detail. I couldn't see any detail at all. It looked like a bowl of quivering, orange Jello. The southern edge did look a little lighter than the rest of the planet. I don't know if this was real or because of bad seeing.
Jeffrey L. Polston