Re: (IAAC) Barnard's Loop, Naked Eye or Otherwise
Bruce Jensen wrote:
> From: "Penny Fischer " <email@example.com>
> >I've seen what I thought was Barnards loop under low power in mediocre
> skies. But try as I might, I could not even imagine nebulosity around
> the Rosette Cluster.
> To actually see the Rosette Nebula, try any very low-power field with an
> O-III filter. Using this combination, it's visible in any scope from an
> 80mm (even binocs) on up. My 8" F/6 used to give a great
> fill-up-your-field view at 37x (35mm eyepiece, 6mm exit pupil). An 8"
> F/5 would have been even better, yielding a little more space around the
> object and giving maximum contrast and exit pupil (7mm). I have to
> admit, were it not for filters, I wouldn't see half the great nebulae up
> >I saw my first views of the NA Nebula this week in my friends
> Obsession, with what I think was an OIII filter, but that object is too
> extended and we could only see a portion (Gulf of Mexico region) of it.
> Still, I have to admit it was a grand object to view.
> I think the Gulf region presents the highest contrast on the NA nebula
> and the sharpest cutoff between nebula and blackness. If you get a
> chance, try a Shorttube or Pronto at low power with an O-III.
> Thanks for your excellent observations and discussion of the Pleiades
> Bruce Jensen
From a fairly dark site in south central Pennsylvania I have observed the
Rosette's nebulosity through an O-III filtered 20" f/10 classical Cassegrain
at 127x. At the opposite extreme I was able to see a part of NGC 2237 as a
dim glow through my 80mm f/5 Orion ShortTube refractor equipped with a 26mm
Tele Vue Ploessl (15x) and an Orion Ultrablock filter on board the MS
Veendam during the 1998 solar eclipse cruise. Of course, in the tropics the
Rosette Nebula was much higher in the sky and it was really quite dark on
the ship's upper forward deck. I've also had some great views of the
Rosette through a variety of instruments at the Winter Star Party.
At this year's Stellafane I had a wonderful view of the North American
Nebula and the Pelican Nebula through Al Nagler's 85mm T V refractor, 35mm
Panoptic, and UHC filter.