by Robert Leyland
| Observer | Robert Leyland |
|---|---|
| Date | 9 Aug 2002 |
| Time | 2200-0130 PDT (UT -7, or 0500-0830 10 Aug 2002 UT) |
| Location | Lake Sonoma CA, 38°43'N 123°02'W Elev ~1400 (Lone Rock Flat) |
| Weather | 22°C Temp, 18% Humidity |
| Seeing | LM 6, transparency 5-6/10, steadiness 8/10 |
| Moon | just past new moon |
| Equipment | 17.5" F5 Dob, 15x70 Binoculars |
A quiet and hot Friday evening, only one other observer with me (Rob Mackie). It is a touch cloudy when I set up, but is expected to clear by 10pm (according to Clear Sky Clocks' predictions).
A new 2" OIII filter, and a 32mm super Plössl from Gary Russell are itching to be tested.
From 10pm to 10:30 or so, I took in some eye candy views of various bright objects with the new OIII filter. Including M8, M16 and M17, excellent views, with wide field 40mm Pentax and 32mm Russell eyepieces. This was dodging early evening cloud cover, but by about 10:45 the clouds had largely departed and I could get back to Aquila, and continue my program.
Beginning with a couple of open clusters, between Delta and Nu Aquila, NGC 6755 a large loose open cluster, with two more concentrated knots of stars, nearby NGC 6756 is smaller, and tighter like a scattering of salt grains.
For NGC 6773, another open cluster, in the charted region I could discern only a very loose conglomeration of stars, no defined cluster to be seen. Sometimes you just can't find the bear.
Ok, planetary nebula time, PK 40-0.1 is difficult, at the threshold of detectability, needing averted vision and motion to spot. Even then it is a bit iffy, just a slight glow.
Next up, NGC 6804, a relatively easy PN, hopping from Mu Apl back towards Altair. A nice circular glow, with a hint of darkness in the interior and a stellar pin prick to one side of center. (100x and OIII filter)
NGC 6781 PN, fairly large and diffuse, at 80x it appears brighter on the S side, shading to a dimmer level on the N. At 210x with the Oii filter in place, it is huge nicely framed in the eyepiece view, and shows a mottled surface.
NGC 6790 - not found - I'm pretty sure I was in the right area, but no show.
Scanning down from Delta to Lambda Aql, is a nice bright double star with an adjacent open cluster (NGC 6775), Easy to find, but otherwise unremarkable, as it seems loose and unformed to me,appearing best at low power.
Adjacent to 6775 is a bright triangle of stars, with one significantly brighter (27 Aql), projecting off along the distaff side (dimmer) towards the next bright star, brings a small fuzzy dot into view. This is NGC 6778 a planetary nebula. At 100x it looks circular but a touch distended. At 210x with an OIII filter it looks like an irregular circle (NSOG describes it as "oval"). It is brighter in the center, and fades a little towards the edges. Dropping back to low power, I can see that the region I've just hopped over is very dark. A check in NSOG, it is B139, a dark nebula.
Continuing the projection off the aforementioned triangle, past 6778, and scanning down a chain of moderately bright stars (8th and 9th magnitude) and we come to NGC 6772 a faint planetary nebula. It is larger (3x) and dimmer (1/2) than 6778, and looks somewhat mottled with an OIII at 160x. It is faint enough to make picking any details out difficult.
It's now 1:30 AM, still pleasantly warm sweater and shorts, but I have to pack up. The evening started out a bit rough, but got better as the night wore on.