Wednesday, September 5, 2001

70 minutes in Hercules and Cygnus

These objects may be pedestrian, but hopefully others will see that backyard observing can be rewarding, even in San Jose.

I put my 8" f/6.9 scope out back after dinner then went out to run some errands. I returned home at twilight and soon was out back with the sky darkening nicely. With the Edmund Scientific Mag 6 Star Atlas, I turned to the first chart with constellations I could see overead. The sky was not dark, but dark enough for some star hopping. While hunting my first object, NGC 6229, I could barely make out 42 and 52 Herculis, both at mag 4.8. and bracketing my target.

NGC 6229 is a bright small globular cluster north of the Keystone toward the Draco border. AT 70x the globular is granular with some hint of individual stars. It is a nice view, as two equally bright stars, the brightest in the field, stand equidistant 8' west of the glob. Nice triangle. At 100x the granularity is more pronounced and the bright core diminishes evenly out to the edges. Seems to be about 1.5' diameter.

NGC 9341, M92 - globular cluster in Hercules. What a veiw after having picked off the smaller glob just minutes before. The view at 70x is fantastic. It is large and bright (by comparison) with many stars resolved over a wide area surrounding a very bright yet rather small core. 100x results in some stars popping out of the core. There are many stars at the periphery, maybe stragglers, that seem to form a rectangular frame elongated N/S. Estimated at 8' overall diameter. Brightest part of the core may be only 1.5' diameter, but there seemed a dimmer second halo of core stars also about 2' wide may envelop the brighter core. The core area appears brighter and larger on the WNW side. Spectacular object!

Looking overhead, I could now just make out the Milky Way through Cygnus. I had to agree, it was "Milky" looking.

NGC 6826 - planetary nebula in Cygnus. Easy to find off the arc of Theta, Iota and Kappa Cygni at the bend of the western wing of the constellation, this is the Blinking Planetary. Aiming the Telrad and looking in the eyepiece, I found a wonderful 70x view of 16 Cygni, the nice close double 30' W of the planetary. The double appeared almost neon-green tinted and lying NW/SE. All I had to do was let the view drift and the target appeared from the E. At 70x it was an obvious small fuzzy star. The central star seemed blue/green at low power. At 100x the central star was very obvious and I could easily perform the trick for which the object is named. Another star of equal brightness to the planetary's central star sits close to the S. AT 195x the halo is very nice... even and gray. I don't know what I was seeing, but at 350x a slight haze to the SE appeared. At that magnification the planetary was slightly elongated NW/SE and gave hints of two shells.

NGC 6866 - Open cluster in Cygnus. At 70x this cluster is obvious. It is not one of the spectacular opens like M11, or the M3x's in Auriga, but yes, obvious and interesting. I thought it was shaped like a flattened "T" ... a long top and a short leg. The long dimension was 18' long laying E/W across the field. The short leg was defined by what seemed four bright stars falling off to the S about 4' in length. All four appeared roughly equal magnitude, but one was actually a double comprised of two dimmer stars that together gave an impression of equal brightness with the other three in line. The cluster has many dim components, which showed more obviously at 100x (as did the little double in the chain of four) and was perhaps more concentrated E of the estimated visual center of the group. When viewing at 100x I had the impression of a bird in flight.

NGC 6910 - Open cluster in Cygnus. Just N of Gamma Cygni. I went to get the 20 Nagler and something bright hit my eye from the E. Moonrise. I was about done. I hunted briefly for the open cluster and at 70x found a small group of stas, just five of them, where I expected the open cluster. Two sets of stars perpendicular to each other, with a fifth bright member between them. Was this NGC 6910? I'll find out tomorrow after some investigation.

I packed up and was inside in 5 minutes. A nice hour+ in Hercules and Cygnus.

The scope is out there still, waiting for sundown tomorrow.

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