[AZ-Observing] Dark Nebulae in Ophiuchus

Hello all;
I had a great weekend last weekend, I was at high altitude in the mountains of 
Arizona, we called the location 5 Mile Meadow, it is near the little town of 
Happy Jack.  I rated the seeing at 7/10 and the transparency at 9/10, the Milky 
Way as absolutely fascinating.  

I got a chance to use my new Rich Field scope, an Orion 100mm (4") f/6 
refractor.  I am very pleased with the contrast and detail in this telescope, 
the fields of view are wide and beautiful, particularly with the center of Our 
Galaxy in good position to observe.  I spent some time with the dark markings 
in Ophiuchus and here are some notes.  I compared my visual observation with 
Barnard's darkness and contrast values, taken from photographs.  He judged the 
contrast of one of these nebulae on a scale of 1 to 6, with 6 being the 
darkest.  Here are the notes from a terrific night observing the sky.

B 44 5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
With the 22mm Panoptic this feature is 4 fields of view long--WOW.
It is never a very dark or prominent feature, but a fascinating
area to scan at low power.  Barnard 44 shows the most contrast
near a double star that is in the middle of this very elongated
feature.

B 45 5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
This dark lane is not nearly as prominent at B 44, it is just
seen with averted vision.

B 59 The Pipe Dark Nebula there are several other Barnard numbers
associated with this prominent dark lane.
5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
Naked eye--an obvious dark marking in the Milky Way, the Dark
Horse figure is quite prominent on a great night in the Rim country.
4" f/6 with 22mm Panoptic is a great view, there is lots of contrast
between the dark markings and the starry background.  I can easily see
the stars that outline the Stem of The Pipe and that this is composed
of several dark areas near each other.  There are dark lanes that
extend north and more prominently to the south of the Stem feature.

B 63 5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
The front leg of the Dark Horse, this extended dark marking is easy
with the 22mm Panoptic eyepiece.  I agree that this is a 6
nebula for darkness and contrast.

B 64  5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
With the 14mm UWA Eyepiece this is a great field of view.
The globular M9 is bright, large, round and much brighter in the
middle.  The dark nebula is about a 5 for contrast so it is quite
prominent.  This dark marking is a thick chevron shape with M9
on the edge.  It looks like "they took all the stars from the
dark marking and put them together to make the globular cluster".

B 72  5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
Best view is with 14mm eyepiece this dark winding lane is easy at
this power.  The contrast and size of The Snake is unmistakable.
Going to the 8.8mm lowers the contrast somewhat and makes the
use of averted vision to see The Snake feature necessary.


B 259  5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
The nearby globular is NGC 6342 it is pretty faint, pretty small,
and little brighter in the middle.  The dark area is a 5 for
contrast so it is quite prominent.  A boomerang of 3 stars encloses
the dark nebula on all sides.

B 276  5 Mile Meadow 4" f/6 RFT refractor S=7, T=9 Wow
In the 14mm eyepiece this dark area is almost the entire filed of view.
The contrast of this nebula is a 5 at best, there are several darker
and lighter regions in this area.

Clear Skies to us all;
Steve Coe

Author "Deep Sky Observing--The Astronomical Tourist"
Saguaro Astronomy Club website
www.saguaroastro.org
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