Observation Log - July 25, 2001

Observation Log - July 25, 2001 - Tinton Falls, NJ

This was a hot and muggy night... 77F and 78% humidity. Thought I would use the poor but fairly clear night to continue working on the Starlight USB interface, and the STAR2000 self-guider. Didn't have much luck with either. I think the USB issue is with the last file I copied over for trying it with AstroArt. In any case, it wouldn't recognise the USB port for any length of time. On the STAR2000, found out that you HAVE to use the standard port on the interface (Not the LX200) and plug that into the CCD port on the telescope. Even at that, I couldn't get it to guide properly for any longer period of time. Need to play with the pixels/sec, and probably with hysteresis settings. Look for these experiments in the GUIDED directory. Any image with a 'g' in the filename was an attempt at guiding. The non-guided images there were tests to see how they looked versus the guided version, and also to see how long I could image unguided. Some 3 minute unguided photos came out well!

After playing with those two items, I moved on to regular imaging. During the course of playing with M57 and M27, I was frustrated in getting poorly shaped stars at the bottom of the field, no matter how I focused. I believed that was due to the use of the visual back, which has the camera inserted just like an eyepiece, and screwed down at just one point. So I tried again to use my short T adapter. With the T in place instead of the visual back, I got GREAT focus. (Remember, I also had considerable problems with focus at Ernie's place, particularly on objects low on the horizon.) But when I took longer exposures, I got the strange arcs and bright spots again. I thought before that those were internal reflections off the shiny inside of the T adapter, so I had painted it flat black before, but that didn't help. Tonight I tried some crude baffles inside the T and the front of the camera. I rolled up a strip of black construction paper and put it inside the T adapter. Then I cut a donut out of the same paper and put it in the front of the camera, against the cover glass. Then I made another donut and put it at the front of the T, just in front of the f/3.3 reducer. Between these three baffles, the arcs and bright spots seemed to disappear. Would need to do a better job with these baffles to make sure they didn't move around or drop paper crumbs on the CCD window.

In any case, with the much improved focus and fixed arc problems, I went on to do some imaging. The sky was so bad I mostly tried just for some open clusters. We'll see later how they came out. So the main configuration tonight was Crayford/f3.3 reducer/baffled T/ MX516 camera with no filters.

Took flats and darks during morning twilight using this configuration. BTW, the first image of 7063 was on the visual back, not the T.

First up was NGC7063, an open cluster in Cygnus. This object is magnitude 7, and is 7' in diameter. The age of this object is 140 million years, and the distance is given as 2,000 light years. This image was made from 12 one-minute images taken between 1:38 and 1:53 a.m. the morning of July 25, 2001, all using the parallel camera interface. For this series, the MX516 was attached with the regular visual back. The images were calibrated, flattened, then aligned and composited in MaxIm. That image was enhanced with a Digital Development filter (Kernel, low-pass), and the resulting image was finished with a contrast stretch.

Next was NGC7142, an open cluster in Cepheus. This object is magnitude 9.3, and is 4'.3 in diameter. This image was made from 13 one-minute images taken between 2:27 and 2:45 a.m. the morning of July 25, 2001, all using the parallel camera interface. For this series, and for the rest of the evening, the MX516 was attached with the baffle-rigged T-adapter. The images were calibrated, flattened, then aligned and composited in MaxIm. The resulting image was finished with just a contrast stretch.

Next was NGC7160, an open cluster in Cepheus. This object is magnitude 6.1, and is 7' in diameter. Distance is 2,900 light years, and age is 10 million years. This image was made from 16 one-minute images taken between 2:49 and 3:09 a.m. the morning of July 25, 2001. The images were calibrated, flattened, then aligned and composited in MaxIm. The image was enhanced with a Digital Development filter (FFT, low-pass, medium), and the resulting image was finished with a contrast stretch.

Next was NGC7128, an open cluster in Cygnus. This object is magnitude 9.7, and is 3'.1 in diameter. This image was made from 9 one-minute images taken between 3:14 and 3:27 a.m. the morning of July 25, 2001. The images were calibrated, flattened, then aligned and composited in MaxIm. The image was enhanced with a Digital Development filter (FFT, low-pass, hard), and the resulting image was finished with a contrast stretch.

Next was NGC7235, an open cluster in Cepheus. This object is magnitude 7.7, and is 4' in diameter. Distance is 12,400 light years, and age is 2 million years. This image was made from 15 one-minute images taken between 3:33 and 3:51 a.m. the morning of July 25, 2001. The images were calibrated, flattened, then aligned and composited in MaxIm. The resulting image was finished with just a contrast stretch.

Next was NGC7510, an open cluster in Cepheus. This object is magnitude 7.9, and is 4' in diameter. This image was made from 15 one-minute images taken between 3:55 and 4:15 a.m. the morning of July 25, 2001. The images were calibrated, flattened, then aligned and composited in MaxIm. The image was enhanced with a Digital Development filter (FFT, low-pass, mild), and the resulting image was finished with a contrast stretch.

The final image of the session was NGC103, an open cluster in Cassiopeia. This object is magnitude 7.4, and is 6' in diameter. Distance is 8,500 light years, and age is 22 million years. This image was made from 13 one-minute images taken between 4:21 and 4:38 a.m. the morning of July 25, 2001. The images were calibrated, flattened, then aligned and composited in MaxIm. The resulting image was finished with just a contrast stretch.