Finally a fine night


jimcoble2000
 

We had a lot of fun under perfect seeing excellent transparency and a cooler evening last night. It is getting darker earlier now so that helps a fair amount.

Before Kent came out I took the opportunity to take some slack out of my mounts RA worm gear. It had gotten way too slack causing the scope to track in spurts that were visible at the eyepiece and the whole thing could be moved noticeably by hand. I removed the cover, loosened the Allan screws and pushed the two block together to remove 99% of the slack. I still left a tiny bit for gear lash. The scope moves much better now and can be focused with out the fov moving. Kent says the mechanism resembles the old Byers mount.

Open clusters were the target of choice last night. These are fun in the suburbs as a less than dark background can make these things stand out by eliminating background clutter. It also makes them appear quite different from observing them in a dark sky. Often you get additional multiple stars as a bonus.

NGC 6871 was an interesting object. A fairly compact cluster that my computer listed as a combination of nebula and open. My chart did not show overlap with the close by SH2 101. The cluster itself is nice. I put in a UHC filter with a wide eyepiece and the surrounding area showed extensive faint nebulocity/opaqueness surrounding the cluster. Kent's six in using an Ultrablock really highlighted the mottled nebula visible even under suburban skies to a trained eye. This would be an interesting object in a dark sky. I will have to follow up on it at a later date. Roy's 3 inch may show this quite well under his skies.

I went a bit off the beaten path to NGC 7209 in Lacerta . This was a delicate fairy dust of a cluster next to a brighter 7th magnitude star. Misty and very pretty. A perfect example of what I was alluding to above. Low power. wide field makes this a fine object in a little visited part of the sky.

NGC 6940 was an example of a cluster that required higher power in order to darken the background. At low power you only get a hint of the cluster's presence. At 120X the fainter stars start to come out in this Vulpecula object. Just the opposite of a wide field object. I used a combination of eyepieces: 10mm Delos, 15mm and 24mm panoptic, and finally a six Delos in reserve for clusters like this. All have a wide FOV and I used the combinations to see what looked best. My main occulars being the 15 and 24 panoptics for this type of work. This gave a range of 40 to 120X

There is a fine triple star in the heart of NGC 4996.

Those were the highlights of a very good night. Heat resumes today.