Lake Sonoma Sat 28 September

by Matthew Marcus


The Clear Sky Clocks (let's hope the Canadians keep paying for it!) indicated a better night for Lake Sonoma than any other of my usual spots, so that's where I went. There was some sort of horse event at Lone Rock, so I went to Gray Pine. Four others decided to do likewise.

At intervals through the night, a car would come in with headlights, make a U-turn, then leave. Someone (I forget who) solved the mystery: we had invaded a favorite make-out spot.

It started out chilly and breezy, but the wind died when it got dark and the temperature held at quite a pleasant level. My policy of keeping layers of clothing in the car paid off.

The Clear Sky Clocks promised good seeing and mediocre transparency. To test the former before it got properly dark, I looked at my usual seeing target, epsilon Lyr. It split pretty well at 125x and Airy rings showed at 250x. Not bad!

A bright object which could only have been the ISS passed over, dropping into the NE, fading and reddening as it went. The crew had just experienced one of their instant sunsets.

Now to business. I decided to go for Scutum while it was still with us. I aimed the scope at what I thought was M24 and found what I thought was 6603, the open inside M24. On reading off coordinates, I found I'd erred - it was the Scutum star cloud and the GC 6712. No wonder I couldn't resolve it! OOPS! I then stopped being a wiseass and used circles to find the real 6603. Whatta maroon!

After that bit of entertainment, I decided to stick with Scutum and check off some more NSOG objects. I got 6649, a pretty OC, then B312, a large dark nebula which looked like an elliptical smudge. It was big enough to be better in the Ranger. My drawing is a bit lame because I did it standing up, but it shows the general shape. Next was an OC, 6645, which I'd gotten before, and which is 2deg S of B312. To be sure of what I was looking at with the DN, I used Uranometria and from that point wandered N. I looked for a reflection nebula around a double star (I forget the IC #; it's in NSOG), but couldn't be sure I was seeing an RN or optics. I really need to replace my scratched-up diagonal! I did get Ruprecht 141, a mid-size OC containing streams of stars, 6683, and OC on the edge of M24, and I1295, a largish PN. NSOG wasn't impressed by this one, rating it as 1*. The photographic magnitude given was 15.0, but I was able to get it pretty easily, so it couldn't have been fainter than 12v. It's a uniform disk, shading away at the edges, with a star on the edge. Although NSOG described it as 'whitish', it responded quite well to an O3 filter. Compared to some of the objects to which they give two or three stars, this one isn't as bad as 1* would indicate.

While looking for some of these objects using 125x, I saw something flashing. First, it was at the edge of the field, and I thought it was a lens-flare off a bright star or something of the sort. Then I got it in the field and saw that it was a nearly stellar object flashing on and off, and bright. At first, it was nearly stationary against the star background, but then slowly moved off. It must have been an airplane way far away and moving almost directly towards us. To remain in a half-degree FOV for a minute or more, it must have been pointed pretty well towards us.

By now, Scutum was getting pretty low. I remembered last week that Robert Leyland had been working Lacerta, so I figured I'd give it a whirl. It's not the sort of constellation you'd normally think of off the top of your head. It turned out that I'd already gotten several objects therein, probably as part of my Herschel 400 survey. Since time was short, I concentrated on new objects, but not before I'd revisited the large, bright OC 7209. I suspect this one would be better known if it were in a more obvious constellation. Continuing with OCs, I got I1434, which I saw as a curved ribbon of stars.

Next up was a mag 12.4 galaxy, 7223, an elliptical fuzz with a star at one end. This was followed by another OC, 7245. Then, despite the prediction of bad transparency, I went for and got a mag 12.9 galaxy, 7242. I didn't get its mag 14 companion, 7240, despite the latter's higher surface brightness.

I had to hurry up on sketching because the moon was coming up. We admired the tawny color lent it by the low-level haze and started packing up. It wasn't until I was all packed up when I noticed Saturn sitting to the right of the moon. Fortunately, Dick had his Tak still out and could point it at the planet. Cassini was a maybe, but I could make out bands and an indication of the planet's shadow on the rings. There's almost no such thing as a bad view of Saturn. With that, I drove out of there, not quite the last out as I usually am.