Saturday, March 31, 2001

Moonlight observing with Mimi

It was the Saturday after the bay area aurora. We headed out to Henry Coe State Park, in order to gain some elevation and escape the potential for increasing wind at Dinosaur Point. Reports from the prior night at Coe was of beautiful balmy conditions, and an awesome auroral display. But this night a steady chilling breeze would keep up nearly all night. We still had a great time observing a handful of clusters and visiting with other observers.

I let Mimi use the 10" f/5.6 and the 8" f/7 scopes I'd packed. Since it was a bright moon night, I decided to leave my big scope hope. Really, the trip that night had been as much to take advantage of any potential residual aurora from the prior night, and to knock off a few more Herschell 400 objects on Mimi's list.

Although there was no aurora, a number of objects were observed before sleep caught up with a young girl who'd been up late with friends the night before.

Targets logged:

NGC 2311 in Monoceros. This is a loose and rather poor open cluster located between Procyon and Sirius. The location is rather easy, other than 3 bright members, the cluster was dim and elusive in the bright moonlight.

NGC 2421 in Puppis. More interesting than 2311, this cluster was fairly rich and large. Two interesting chains of stars ran NE/SW either side of the group. The chain on the SE side was more defined, more linear, the one opposite the cluster was more scattered. Nice view. We had come off of M93 very closby to find this one.

Again in Puppis, Mimi moved to NGC2438 and NGC2437. Not knowing what to expect, she found herself viewing M46, and noted the little puff of a star sitting there. That was 2438, the planetary nebula foreground to the famous Messier. Dim, but there, in the moonlight. NGC2437 was noted, just because it was there... M46. This was a very nice contrast with M47, next door. Where M47 is coarse and bright, M46 is delicate, evenly distrubuted, contains more stars and are dimmer overall.

Mimi was surprised to find she'd already logged the next object on the H400, it was M47. But, just north was her next object, NGC2423. It is a dimmer, and again, delicate open cluster. Really rather pleasing, especially being able to move swiftly between M46, M47and NGC2423. A wonderful area to view. And, easy to get to... Mimi had picked the clusters out unaided in the bright moonlight.

Now it was time to tackle another planetary, NGC2440. Mimi used some interesting navigation to locate this dead star. Starting with naked-eye M47, she picked out mag 5.3 SAO 174592, which is the middle star of the three bright ones just east of M93. She told me the planetary should be about one third of the way from M47 to the star. She tried with the 8" without success. Using the 10 though, she was on it in a flash. With a 20 Nagler yielding about 75X, the little ball was obvious.

By now, Mimi was tiring. The chill wind was a constant. The warm nights of a few nights before had given over to winter again. Soon, she was sleeping in the back of the truck, tucked into a sleeping bag. I visited with friends for a while more, watching for the elusive aurora.

Mimi slept all the way home. She is now almost halfway through her Herschel 400.

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