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While this region
is far too low to image properly at our backyard observatory
in Payson due to nearby pine trees, it is available for hours
at a time at our observatory in Happy Jack. Also, the higher
elevation makes a big difference (7000 feet) because the transparency
there is so much better. The small red nebula seen in the telephoto
shot in the upper image is IC4628 an emission nebula which is
actually quite faint and diffuse. The surrounding field contains
several bright open clusters, brilliant star fields and a background
of structurally detailed Milky Way.
Two images that were
taken at the same time are shown here. The upper image is a test
shot with our 150mm f/2.8 Sigma macro lens. It is an incredibly
sharp lens for close ups of flowers and small wildlife, and it
was good to test it at night to see if it would be equally good.
The short analysis here on that is that it is very difficult
to get in focus on stars because it is so fast, and apparently
my Canon Xti camera has a tilted sensor - the stars on the left
are not quite as sharp as on the right. The "Star Test"
is brutal!
Ive inserted a frame
into the upper image to show the framing of the lower image taken
with the Stellarvue SV80S and OSC CMOS camera. The larger aperture
and longer exposure (90 minutes) made all the difference and
revealed that the entire field is filled with gorgeous red hydrogen
nebulosity. Several bright star clusters were also included in
this field. Take notice of the dark band extending to the upper
right from the main nebula. This dark nebula is called an "Elephants
Trunk Nebula" because of its shape and is common in many
emission nebula.
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