by Albert Highe
For a change of pace, and a desire for a quick get-away if need be, I took my little 6" f6 portable dob to Dinosaur Point on Saturday. This is the scope I usually take to star parties because the eyepiece is conveniently located for kids. It is also an open tube, so I can easily point out the optical elements and explain how the telescope works. I also use it for quick looks in town since I leave it set up and can carry it outside in about 30 seconds (17lbs total weight). So, if I decided to leave Dino early, it would take me less than a minute to pack up.
I am usually disappointed by views in town through the 6" because of light pollution. Although we had a fairly bright 1st quarter Moon, the skies at Dino were still darker than in town. Saturday night, the skies at Dino were very clear and transparent. Despite the Moon, M31 was still a naked eye object. I could make out the Milky Way. As already noted by others, seeing was rather soft. I didn't go much above 125X. I could make out the Cassini Division in Saturn's rings and the warm brownish yellow band on the planet itself. But the view kept swimming around. Likewise, I could see multiple bands on Jupiter and occasionally glimpse Io's shadow when seeing permitted.
The 6" is set up with only a lightweight 1X red dot finder. This is plenty for finding most Messier objects where I can see stars (like at Dino) or bright planets. For star hopping, I used a 25mm Plossl eyepiece that provides nearly 1.4° f.o.v. at 37X. That is quite a bit narrower than I am accustomed to with the 80mm finder on my 12.5" scope. In addition to adjusting for the different scale, I also had to adjust for different star brightness.
Finding Messiers was quick and much more rewarding than I had anticipated. With the 25mm eyepiece, the Pleiades cluster was nicely framed. This is a great magnification to view this cluster with. I never see it this way in larger scopes. Likewise, M31, M32, and M110 all fit with room to spare (except for M31 spilling over the perimeter of the eyepiece). I could just detect the major dust lane in M31. M32 was a bright ball, fuzzy at the edges. M110 was larger and lower surface brightness with a hint of a brighter core. Nice even with direct vision. I was quite surprised a small scope showed so much (I had forgotten). I have to make sure I return with the 6" when there is no Moon.
I continued viewing other favorites, like the open clusters in Auriga. Once I located them, I increased the magnification to 73X, using a 12.5mm UO ortho. This is an excellent, low-cost eyepiece with excellent sharpness on-axis and great light throughput. I always start with the bright asterism in the middle of Auriga and use it to point the way to M38. Of the three Messier open clusters in Auriga, this is my second favorite. It is a nice rich collection of moderately bright stars. Like M35, it has a smaller and fainter open cluster, NGC1907, nearby. It appeared as a faint glow with direct vision. I couldn't quite convince myself I saw individual stars. Next, I hopped to M36, which I find rather uninteresting. It's a collection of fewer, but brighter stars. Mostly it's a signpost directing the way to the real show, M37. I routinely look at this open cluster with the 12.5". But even in the 6" I find it a stunning object. I have always been fascinated by the hundreds of faint, well-resolved stars. It's one of the first Messier objects I ever found and seeing it always reminds me of my observing roots.
Next I swung the scope over to M35. Its stars are much brighter than M37, but I don't find it quite as appealing. Likewise, its small companion open cluster, NGC2158, was an obvious small, dim glow.
Orion was beckoning, so I swung the scope over to M42. This view also surprised me. Last weekend I had some stunning views of M42 with my 12.5" from superb skies. I was impressed by the detail I could see with the 6" with the Moon still out. The wings extended almost across the f.o.v. of the 12.5mm eyepiece. The contrast was very good and I could make out variations of intensity across the central section. The bright comma-shaped M43 was obvious across the dark gap separating it from M42. And I could even detect some of the fainter nebulosity NGC1973. I, most definitely, have to bring this scope to dark skies.
I could belabor the views of other Messier objects, but let me just add that I was also duly impressed by views of M1, M81, M82, M46 (planetary nebula easy), M47, M97, and M108. M81 and M82 were particularly nice, framed together. M82 showed distinct mottling.
Having so much fun looking at easy stuff, I thought I'd try something more difficult. Just as I had that thought, Jamie D. mentioned NGC2419, the globular cluster known as the Intergalactic Wanderer. Coincidentally, my Sky Atlas 2000 was opened to that page, so I gave it a try.
Starhopping with my 80mm finder on my 12.5", I would have found it in a couple of minutes. However, this is where I found myself having to adjust to the unfamiliar f.o.v. and star brightness. It probably took me 20 minutes to make the adjustment and star hop the 7° from Castor. But the journey was worth it. NGC2419 was visible with averted vision as a moderate size diffuse ball. Two approx. 8th magnitude stars point the way. I suspected that others might doubt such a report so I asked Bob Cz. to confirm. He saw it as well. Having made the adjustment and found it, I could return to it within seconds. I looked at it about a half-hour later, when the Moon was lower in the sky and casting less light. I could then see NGC2419 with direct vision. No doubt in dark skies it would be a rather easy object with a 6".
Armed with this success, I looked for other nearby, interesting and challenging objects. The irregular planetary nebula NGC2371-2 is within Gemini, approximately 3° SW from Castor. I found this 13th magnitude nebula after about 10 minutes. It appeared as an elongated dumbbell-shaped object with averted vision. One end was slightly brighter than the other. I then asked Bob Cz. to point his 12.5" at this object. With the larger aperture, a lot more detail is visible. It is clearly two-lobed, one disk quite a bit brighter than the other, apparently with a brighter central area.
At about 10PM, some high thin clouds started to roll in. I took that as my cue to leave. By that time the temperature had dropped to 44°F with an RH of 55%.
Normally I wouldn't have posted a report about observations with a 6" scope. TAC seems to have a bias toward observing faint and obscure objects with large aperture scopes. However, the night had been so much unexpected fun, I had to share it. Besides, I hope it will provide others some encouragement to take their smaller scopes to dark skies and to post their observations.