Nebula Dark and Planetary - Aquila Part Three (10 Aug 2002;

by Robert Leyland

I arrived a bit before 7pm, to find Matt Marcus setting up, and for a while it looked like it might just be the two of us. Then right around 8pm half a dozen vehicles arrived within about 5 minutes, and we had a full fledged group. Matt gleefully noticed that for once the Dobs were outnumbered by SCTs, as we had David Silva, Dick Flasck and myself with Dobs, and at least six 8 to 11" SCTs. Dick pointed out, that we had them beat on combined mirror area. Later in the evening Bruce Jensen joined us, and although he setup at the other end of the lot, it did help even out the ratio.

Early evening views were quite encouraging, there was a touch of cloud moving slowly eastward, far less then the previous evening. Earthshine illuminating the setting crescent moon, and a half phase Venus were were quite steady, even though they were fairly low in the sky. I star tested on Polaris for fine collimation, and got a nice steady airy disk.

Linda Mahan had another object-du-jour, with charts, for the "other double-double" in Lyra. (project off the short leg of the parallelogram nearest to Vega, to find a widely spaced pair-of-pairs). Each pair is parallel, and well separated, with noticeable primary and secondary components. Each feature contrasts with Epsilon Lyrae as they are at right angles, close, and even brightness pairs. Epsilon Lyrae is no slouch, splitting easily at 160x, and again with very nicely defined airy disks and diffraction rings.

Seeing is very steady, did I mention that already? We got great views of M22 at 425x, resolvable stars and steady. David Silva went for some stupid high powers, barlow-ing his 3-6mm zoom, with astounding success. It was one of those nights you really look for, and want to savour.

So while conditions are good I want to retry a couple of poorly seen and missed objects, in Aquila, from the night before.

NGC 6790, faint stellar PN, blinking an OIII filter helps to spot it, and at 320x it shows as a small disk.

NGC 6778 has nice elongation in the PN, with some extensions or lobes. It looks a little like the mini dumbbell.

NGC 6772 PN very nice at 210x with an OIII. When sharing the view, each observer noticed that the surface was mottled or disturbed, but is was hard to agree on the description. I saw a V shaped brightening, and two small arcs of darkness.

Continuing my survey of Aquila, and scanning down towards Lambda are two noticeable voids in the starry backdrop (B135 and B136). Then, off Lambda are two double stars, one a close pair, and the other widely separated, between these pairs and Lambda lie two further dark nebula (B132 and B328), which look like irregular black patches.

PK 33-5.1 planetary nebula in Aquila, this is dim, I can only just hold it with direct vision, while averted vision at 210x with an OIII filter shows a round blob, slightly brighter in the center.

Near lambda, and forming a triangle with 12 Aql, is NGC 6751, a nice PN, somewhat annular with a bright central star, a great view at 320x. Droppig back to 100x the PN is obvious, as are two nearby dark nebula (B133 and B134) which show as two blank spots in the star field, each a shading darker in the center.

Backtracking up the center line of Aquila and moving east brings me to NGC 6741, a nice bright planetary nebula with two faint stars adjacent. This PN looks a little bit oval in shape, like a circle just a tad out of kilter.

The next object breaks the trend, being a globular cluster. NGC 6760 is moderately sized, but faint. It looks flattened when compared to the bright globulars, considering its location near the galactic ecliptic perhaps some dust is extinguishing the brightness.

Another globular nearby, NGC 6749, is seen as a diffuse glow, it is hard to distinguish from the large number of foreground stars in the area. I may not have caought this one, so I'll try it again on another night.

Back to the nebulae, dark and planetary, PK 36-1.1 shows up as a round glowing spot with soft edges at 210x an filtered. Averted vision reveals an annular shape, slightly darker in the center, and quite faint.

Off Lambda are more dark nebula, a small group of three B127, B129 and B130. Teardrop shaped, and clearly darker in the center.

Wrapping up the evening we follow Bruce Jensens suggestion, and Matt and I attempt to find Pease I, a planetary in M15. Using an OIII filter & blinking I could see a "star" near the edge of the globular cluster that didn't go away with the filter. This is pretty cool, but ultimately we aren't convinced that we really had it. Worth trying again, when I am not as tired.

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