Lake Sonoma Sat 31 May 2003

by Matthew Marcus


The sky was better than it had been the last several times I was out, and so I took full advantage by staying all night. The relatively good conditions drew a good crowd including a number of people I hadn't seen in ages. Nice to see you again, folks, and nice to meet the rest of you! Congrats to Dave Windstrom on succumbing to aperture fever (in a limited way) and upgrading to an 8". I had fun comparing views with him.

Transparency was middling at the start, with low-level haze expanding the light domes to N and SE, but improved as the night wore on, then getting somewhat worse again after about 3AM. Seeing was soft, with intermittent steadiness, much worse low in the sky. This suggests that the problem was local, perhaps correlated with the wind which kicked up at times. It was a warm wind, though, and dry, so it was quite comfortable.

We all started with Jupiter. Dave W. got there first with his whizzy new GPS-enabled C8. He could get it with the sky still blue. Ganymede transited the disk, but the seeing was poor enough and the planet low enough in the W that we couldn't get the shadow transit. Oh, well.

There were quite a number of bright, fast meteors, including one which considerately burned up in the direction of Jupiter, where most of us were looking. That one left a trail of sparks. It seemed that many of them came out of the E, as if part of a shower, but there were no showers scheduled.

As the night started to get dark, I picked my first DSO to be one which could stand a little light and was in a direction I planned to be looking in. Thus, I hit M3, which is always worth a look. Later, I got M51. It would be a criminal waste to miss that one with CVn high in the sky.

Thus I began a dive into the galaxy-littered realms of Canes Venatici. We were wondering whether it's pronounced "Ven-a-teech-ee" as it might be in Italian or "Ven-AT-ick-ee" as I was doing. Someone who knows Latin might be able to help on this score. I just (this second) realized that I should have looked in NSOG, as I think it has a pronounciation guide.

To ease into faint-fuzzy mode, I went for 4631 and 4627, which are a pair half a degree apart. 4631 is a splendid edge-on with hints of mottling, sort of the North's answer to 253. I could clearly see that one end was brighter than the other. 4627 is the 'hocky-stick' galaxy. I could just make out the 'blade'. Steve G. said that there was a suspicion that these two are actually parts of the same galaxy, though that seems hard to believe.

On the way to the first search target for logging, I looked at another pair, 4485/4490. This close pair looks like the Intel Centrino logo, though not red and blue. That first target was 4183, a very faint streak with some brightening in the center, floating among stars.

A couple of other targets were close to M106, which by comparison is huge, bright and detailed. One edge seemed sharply cut off, presumably by the dust lane. Hopping from there, I went to 4217, which was just off a pretty field of fairly bright stars. I wonder if those form a cluster or a multiple.

"Cleaning up" the CVn list, I hit the unremarkable-looking galaxies 4220, 4242 (a faint round haze with no visible core, suggesting a large, faint PN), and 4357. Somehow, I had managed not to log 4244, a very long, thin streak of an edge-on. This one will be worth more looks. The omission is hereby taken care of.

Pluto was nearing the meridian, so I went for it, intending to confirm last week's observation. Unfortunately, the predicted position was right in the midst of a pretty little group of faint stars, and the chart was on too small a scale for me to be sure which star was the planetary imposter. I therefore was unable to log it. I did, however, look at the position I sketched last week and confirmed that the dot of light I labeled as Pluto was no longer there and everything else was. I therefore claim confirmation of my status as a Plutocrat.

That took long enough to let CVn go down some, so I went for some targets in Hercules. M13 did not escape my attentions. I logged 6052, a faint, tiny galaxy, DoDz 7, a Navarrette-style OC, and 6482, a round mag11.4 fuzz with a visible core, which is made harder to see by the presence of lots of bright stars.

Speaking of bright stars, Steve showed off a mag 15 galaxy very close to 3rd-mag delta-Leonis. It took 300x to be able to get the star out of the field and even then scattered light made a spike in the field. That's the most extreme example I know of a faint, amateur-accessible object being obscured by a bright star.

I hit some favorites in Sgr and Sct, including M11, M8, M20, etc. Nice to see our summertime friends again!

Next, I went into Aquila, a constellation that's lots bigger than I thought. It extends all the way out to Scutum, which is a long way from its alpha, Altair. This constellation is home to lots of dark nebulae, of which I logged only one, LDN582. This is a long, thin 'crack' in the Milky Way starfields.

There are also lots of PNs there, a refreshing change from the spring galaxy glut. I got 6772, 6781 (round, but fades off to the N and has a barely-visible hole in the middle) and 6582.

By this time, it looked like transparency was going to hell, but it was really the approaching dawn. I hit one last object, M15, and packed up at 4:30 and went home. Venus rose while I was on 101, and the Sun while I crossed the Richmond-San Rafael bridge.