Observation Log – Thursday, July 1, 2010
Date: 7/1/2010
Time: 9:15 PM – 11:00 PM EDT
Scope: Celestron C6-SGT and Astro-Tech AT66
Eye Pieces: 22mm Panoptic, 9mm Nagler, 7mm Nagler, 4mm Radian
Weather: Cool and clear
Moon: None
Alignment Stars: Arcturus and Spica
Calibration Stars: Antares, Deneb, and Altair
My observation plan was to observe a few globular clusters. I was looking for targets to possibly image over the weekend. The sky was very clear, I don’t think we have had skies this clear since early spring.
Since I had to get up early the next morning I did not get to spend as much time out as I would have liked. I spent most of the session observing M13 and M92. I also took a quick look at M4, M5, and M80.
From my observing notes:
Messier 13 (M13), the Great Globular Cluster in Hercules, was the first on my list/plan. Was able to see the cluster with the 22mm Panoptic in the C6 and I was able to resolve individual stars on the outer area of the cluster. The heart of the cluster was fuzzy without detail. At 9mm I could resolve individual stars closer to the center of the cluster and the 7mm Nagler showed even greater detail of what appears to be 100s if not thousands of stars.
With the 7mm Nagler in the AT66 the view was similar to the 9mm in the C6. A wider area but good contrast and I was able to see individual stars close to the center of the globular. I tried the 4mm Radian but had a hard time focusing. The scope was pointing nearly straight up which caused the Crayford focuser on the AT66 to slip from the weight of the eye piece – no issued with 7mm Nagler (which is considerably lighter). There is a tension adjustment on the focuser but it requires a small allen wrench and I did not want to fiddle with it in the dark.
Messier 92 (M92) – With the 7mm in the C6 I was able to resolve individual stars. This globular cluster seems much more compact. More stars in a smaller area. Did not take up as much of the FOV in the 7mm eye piece as M13.
I got a quick view of M4, M5, and M80 with the 9mm Nagler and the C6. I did not spend the same amount of time on these that I did on M13 and M92. The one note that I did make about M4 was that it appeared to not contain as many stars as M13 and M92.
I had great views of each of these globulars and I think M4, M5, and M80 will be on my list of targets for imaging this weekend.
Before ending the session I took a quick look at Saturn. The planet was much lower in the sky, near the horizon, so I did not have the same issue with the 4mm Radian slipping in the AT66. I could easily resolve the ring shadow where it crossed the planet. The 4mm in the C6 also allowed me to see some good detail.
