Jupiter Occultation of 45 Cap

Date: 2009-08-04
Time: 3:24 UT
Location: Snellville, GA
Telescope: Dob 10-in f/4.5 and also stopped down to 3.5-in f/13
Magnification: 114x
Objects: Jupiter, Europa and 45 Cap
Seeing: 4 (1--4)
Atmosphere: Humid, slight clouds. Clear around Jupiter during observing.

45 Cap and Europa had already emerged when I began observing. Europa was barely separated from the limb. Here are some (badly typed) posts from Twitter.

with Dob 10 f/4.5 Europa is just off the limb 2009-08-04 03:24:59 UT

Now four obj following. Closest is maybe 1/6 Jup diameter from Jup and right on the equator. 2009-08-04 03:47:41 UT

Europa was clearly separated and visible. The occulatation was actually over when Jupiter rose since the emergence time of 45 Cap was really 1:00 UT. I was confused by the S&T article and thought it emerged at 2:39 but that was the Io emergence time.

Here's a “sketch” made with MS Paint at 2009-08-04 12:48 UT, some hours later.

Seeing = 4 (1--4). Excellent belt detail. 2009-08-04 04:02:00 UT

Seeing was quite good after the telescope settled down. I observed with and without the aperture mask. I was going to try out the Pickering scale on a star, something I think I used to do many, many years ago, but forgot to do that as I was putting the telescope up.

there is a daek feature in the NEB that extends to the following side. 2009-08-04 04:03:03 UT

(More bad typing. daek = dark). Near the central meridian (CM) was a dark spot in the North Equatorial Belt and it looked like it was part of a dark feature that extended from the CM to the eastern side. I've represented it roughly in the above sketch.

I'm using a hand truck to move the telescope around. The problem is the telescope ground board and box are long enough that the whole thing wants to tip forward when trying to rock it back on the hand truck. My current solution is a piece of very strong string/cord looped from one brass handle, around the hand truck, to the other brass handle, and then wrapped a few times around the top of the handle where my hand is. That's enough to keep the telescope from tipping forward.