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CCD project - 2001 February 17, with Bill and Ellen Bryson

Here's what Bill and Ellen had to say about this session:

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There have not been a lot of good weekend observing nights this winter, so when I signed up for a session with Craig Tupper and the Novac CCD project for myself and my 12-year-old daughter, Ellen, I was afraid we would be clouded or snowed out. The week beforehand was overcast, which did not bode well for us. But at mid-afternoon on the appointed day, a cold front blew through and chased the week's cloud cover to the east. The trouble is, as is usually the case with clear skies in winter, you pay a price. This cold front was quite strong, with sharply colder temperatures and very brisk winds, so my daughter and I bundled up with everything we own by way of cold weather gear and headed out to Mickie Gordon park to meet Craig.

We were late getting there, and when we arrived, Craig had already set up the 10" Meade LX-200, the SBIG CCD camera, and his laptop, which he operates from under the hatchback of his car. He had already finished polar aligning the scope and was working on bringing the system to focus, which is, of course, harder with a CCD system than visually, where feedback is instantaneous. Within a few minutes, however, he had the focus just right, and we were ready to go.

Ellen and I had devised a target list for the session, consisting of some objects that she has enjoyed visually as well as a selection of objects of different kinds, with some edge-on galaxies thrown in (edge-ons are among my favorite visual targets). I wanted to try some objects that were too faint to see well visually in my 15" reflector as well as some objects that I had seen many times, just to get a sense of what the CCD camera could do, particularly in short exposures. We began with M-1, the Crab Nebula. Craig brought the object up on his computer and used the computer to direct the telescope to it. The Meade whirred and stopped near the zenith. Craig took a five-second image just to see if we were in the right spot, and sure enough, after a few seconds of processing, the Crab Nebula showed up on the screen. I was very impressed with the amount of detail the CCD camera was able to capture in only five seconds-much more than I have been able to see visually. Craig then made a one-minute image, and it was stunning. M-1 is one of the faintest Messier objects, but the CCD image was very bright and structure was easy to make out. Even more impressive. the image showed no blurring, even though the winds had been kicking up during the one-minute exposure. Craig has modified the Meade LX-200 system in several ways that have produced an exceptionally stable and precise tracking platform for the CCD camera. Despite the heavy winds-and the winds were very brisk throughout the evening-the system produced remarkably stable images throughout. In fact, only a couple of times all evening did we have to reshoot an image because of wind-induced wobble. Winds that would have blown my truss-tube reflector from Fornax to Cepheus did not budge Craig's setup by even a few arc seconds!

We next tried for M-82, one of my favorite galaxies. It is also one that Ellen enjoys, because she can see both M-82 and its companion, M-81, in the same low-power field in her 6" reflector. The shot of M-82 was spectacular. Visually, I can just make out one dust lane in the galaxy, but with the CCD camera, we could easily make out two lanes, and there was structure throughout the body of the galaxy, including both bright and dark areas. What impressed me most was that, unlike some CCD images of galaxies, which are overexposed to pick up spiral arms and therefore do not show structure in the inner area, Craig was able to use short exposures to bring out lots of structure in the inner areas.

We moved on to numerous other objects. Craig let Ellen try her hands at the controls of the computer, which was a huge charge for her, and Craig encouraged us to take an active role in the process. I was amazed how many objects could be imaged in a short time. Each time the scope slewed to a new object, it was right in the middle of the field, plus or minus about 3 arc minutes, which is astoundingly accurate for a go-to system. The Meade-Tupper system was right on the money. Then, in a minute or so the exposure was done and the image began to emerge. I could see why CCDs are so useful for programs such as supernova searches. You can cover a lot of ground in a hurry.

Two of my favorite visual galaxies, NGC 2683 and NGC 2403 were next. Both are big, bright spiral galaxies that show some structure visually. The CCD shots were excellent, showing spiral arms and lots of structure in each. I then suggested that Craig shoot for NGC 2419, the so-called intergalactic tramp, a very remote globular cluster in Lynx, which is located far from the Milky Way. It is visible, but unresolvable in my 15", but the CCD image showed terrific resolution, and it made a lovely pair with the bright star that is only a few arc minutes from it.

The edge-on galaxies that I had on my list, NGC 2357, IC 2233, and UGC 3697 were all very impressive. Sometimes edge-on galaxies can be difficult to find in less than ideally black skies, as they don't stand out too well. These stood out very well indeed. Even the so-called "integral sign" galaxy, UGC 3697, which is too faint to be seen well visually, was readily visible and actually did look like an integral sign in the image. The other two edge-ons are two of the thinnest edge-ons I know of, and sure enough they showed up as bright, spindles suspended in the field. Quite a sight!

A side note. When I got home with the disks with the images on them and put them in my own computer, I noticed a bright star smack dab in the middle of one of the arms of the edge-on galaxy IC2233. I hadn't noticed the star in the image we looked at in the field. Of course, my heart began to race as I thought that perhaps we'd come across a supernova! I follow the supernova reports and had not seen one reported, but then perhaps IC2233 is not on the principal search list for the several supernova search programs that pick off most of the new ones these days. I first checked the minor planet website to see if there were any asteroids in the vicinity on the night of February 17, and none showed up. But then, holding my breath, I downloaded an image of the galaxy from the digitized sky survey, which was done at Palomar some years ago and is now available on the internet. Alas, there was my "supernova" right where the CCD image placed it. So much for discovering a new supernova. That star, no doubt a (relatively) nearby star that just happened to be superimposed on the galaxy, did such a good imitation of a supernova that I took solace in the fact that others have surely done just what I did-getting excited about the star until they checked a photo of the galaxy.

We also looked at several objects from the Arp Catalog of Peculiar Galaxies, many of which are clusters of very faint galaxies. Those objects made the CCD camera work a little harder, but it still pulled them up very nicely. I tried a Hickson group just for fun. Most of the Hickson groups are very difficult for visual observers, and many of them have broken my will after long periods of hunting and just giving up. Hickson 31, on the other hand, submitted meekly to the CCD camera. The cluster was right there, fat and happy in the middle of the screen, looking even better, actually, than the photo of the cluster that is included in the Hickson catalog itself. In looking at the Hickson groups, another advantage of CCD imaging struck me. We were scanning the image to see if there were any faint cluster members there, and since several of us could look at the screen at once and point to particular objects, we could compare notes in a way that is impossible when one person is at the eyepiece and another is trying to direct the observer's attention to a faint object that the observer is having a hard time locating.

After a few other galaxies, the cold and the wind were taking their toll, so we ended the session with one of my favorite objects, the Flame Nebula, NGC 2024. Normally, the Flame is over-exposed in large-scale photos that also take in the Horsehead Nebula, and not much detail is seen in the Flame itself. The image we got, however, contained a staggering amount of detail. The Flame is pleasing visually, but lacks crisp definition in my 15" scope and none of the intricate internal structure is visible. In the CCD image, by contrast, there was an amazing amount of detail. Quite an object to end our session on.

In every way, the session was a splendid evening of learning, and discovering a new way to enjoy the sky. I don't think I will give up visual observing, but I have a new level of respect for what this technology, in the hands of a skilled operator, is capable of. The downside, of course, is that on the way home, Ellen asked why I couldn't do the same thing.

Ellen and I are immensely grateful to Craig for taking the time and subjecting himself to the cold in order to give us this insight into the world of CCD imaging. The club is very lucky to have someone who is willing to share his talents in this way.

-- Bill Bryson, Ellen Bryson

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	NGC 2683. 60 second exposure.
	NGC 2403. 60 second exposure.
	NGC 2419, the "Intergalactic Tramp", the most distant globular cluster in the neighborhood of the Milky Way. 60 second exposure.
	NGC 2357. 60 second exposure.
	IC 2233. 60 second exposure.
	UGC 3697, the "Integral Galaxy". 60 second exposure.
	NGC 2024, the Flame, or Train Track, Nebula. 60 second exposure.
Here's a couple images I shot after Bill and Ellen left:
	M104, the Sombrero Galaxy. 60 second exposure.
	M97, the Owl Nebula. 60 second exposure.