June 20, 2009: Plettstone

Bill Cone

Flying into Oakland from Burbank last Thursday afternoon, as we began our descent south of Pacheco pass, with Dino below, my eyes wandered across the valley, to Los Banos, tracing a road east through the agri-grid in the afternoon haze, the city of Merced barely visible as a textural shift, with the distant curving green swath signaling the Merced river drainage flanked by the golden foothills. Plettstone is somewhere to the right of that drainage, further beyond those golden hills, slowly sliding to the right, out of the field of view of my 'porthole into space'

For the last 2 new moons, Patty and I have driven to Plettstone, Michelle and Paul's property, just off of Highway 49, near Mariposa, enjoying their generous hospitality, tasty BBQ, dark skies, and some good observing company. Last Saturday's trip was as good as the previous month's. We followed a line of clouds all the way to their property, arriving before 6, and by the time we were done eating, had set up the scope, the skies were clear. Present this month were Albert Highe, Gregg LaFlamme, Mark Johnson, and Rob Hawley. Michelle had the observatory open and set up with 2 scopes on a massive equatorial pier, her AP 130 Starfire, and a Tak Mewlon, through which she shared some sharp views of Saturn.

Following a quick nap after a fine summer dinner and sunset I got up and started poking around. I've been busy in other aspects of my life, so have not spent much time planning observing sessions or making charts. I did bring various atlases though, and had a great time wandering through areas of the sky. Similar to some of our drives to and from Plettstone, where we've taken back roads to explore the territory off the interstate, I've been enjoying starting with a nice piece of eye candy, then studying charts to see what is nearby, and just moving from object to object until I lose interest, then pick another bright object, and go wandering on the chart around that region. Last month, I started at M104, the Sombrero galaxy in Corvus, then followed a curving chain of ngc globulars and galaxies through Hydra, Centaurus, Lupus, and Libra, ending up at M5, before stumbling onto a relatively rich group of galaxies about 2 degrees west, known as the 5846 group, according to Finlay's Concise Catalog of Deep-Sky Objects. The Pocket Sky Atlas shows 4 galaxies in that region, while Uranometria shows about 10 roughly within the same 1° square, with more nearby, not that I could see them all, though I did pick out UGC 9732, and MCG +0 39-4, lurking about .5° southeast of 5846. I revisited the group this month to examine it a bit more. NGC 5846 has an 'a' component, which is visible as a star-like blob just south of the glow of the larger galaxy. It looked basically stellar to me, so I asked Greg to pull it up in his 22". 2 objects bright and clearly visible, one very much a galaxy, and the diminutive companion, showing no structure or extension of form. A DSS photo I pulled up later did show a glow around it.

While loitering at Greg's scope, I asked to see the Cat's Eye Nebula, a large planetary in Draco that I'd had trouble seeing much detail in with my 18". I could see an extended green elliptical ring around a central star, but I recalled Greg singing the structural virtues of this object up at Bumpass. I found even through the 22" that I couldn't resolve the details that Greg could describe to me when he looked at it. My eyes may be worse than I thought! Greg then showed me the 'pillars of creation', a portion of the Eagle Nebula made famous by a Hubble photo. I could make out one inverted blobule adjacent to a star, similar in low contrast to the Snake Nebula. Dim, but rewarding nonetheless. Onto more eye candy. Through a 22" everything is a bit brighter and often well magnified. Greg pulled up the Trifid, and it was probably the clearest view I've ever had of that object, having first observed it back in the mid 90's through my UO 80mm refractor in central Oregon, then many times through my 10" Starsplitter. I don't recall looking at it through my 18" yet. The Trifid was clearly divided into 4 parts by dark lanes, from what I could see. Also interesting was the color sensation of the brighter elements feeling cool and the darker ones feeling warm, though they were all grey in color. The hits kept coming. Did I mention the Swan, or the Veil? I had already worshipped at the altar of the veil in my own scope earlier that evening, but enjoyed moving through the myriad of wisps and tendrils in the 22". Greg has built a beautiful scope, and deep sky eye candy has never looked better to my eyes. Thanks!

Satiated with those views I wandered back to my scope and resumed my back roads journey, starting on NGC 5746, a galaxy in eastern Virgo that has been the subject of praise in numerous ORs on TAC over the years. About .5° west of 109 Virginis lies a beautiful edge on, oriented N-S, dustlane visible crossing the core, with a field star on the southern end, and a curving line of 3 stars off the northern end. Two less distinguished galaxies, 5740, and 5738, form a curving chain to the southwest. About 2° to the south of this group lies another galaxy trio, 5719, 5713, and 5705, forming a right triangle, with 5713 being the brightest and 5705 the dimmest. 5691 lurks quietly just out of the field to the west.

About 5° to the east l observed another grouping located less than a degree west of 110 Virginis, 5806, 5813, and 5814 (a dim little thing). 5813 was the brightest, and distinguished by a symmetrical diamond of stars surrounding it that I sketched.

I peeked at one of my summer favorites, the Inkspot, B86, and the OC NGC 6520, wavering away down low, then slid the scope over about 20' west, spying the small trapezoid of stars, similar to Hercules, that Paul Alsing had described to me several summers back at Shingletown in the middle of the night. Within that trapezoid was a small, granular glow- Djorg 2, a faint globular and former astro-concentration subject. Funny when an obscure deep sky object triggers memories of the past.

It was a great evening and a good way to get back into observing, what with the company, the dark skies, and the generous hosting of Michelle and Paul.