clear sky chart

Job 9:9

Job 9:9-10
9 He is the Maker of the Bear and Orion,
the Pleiades and the constellations of the south.
10 He performs wonders that cannot be fathomed,
miracles that cannot be counted.
NIV

Saturday, August 6, 2016

Iris Nebula, NGC7023

The Astro-Tech focal reducer/field flattener that I'm using with my AT-72ED has threads to accept a 2" filter.  I was looking thru Amazon and found a very low cost light pollution filter (in the $35 range).  So I bought one.   It is just enough to get some rather deep images from my moderately light polluted sky.

I have been having a great time taking wide field images, even of small objects that I would normally use a longer focal length.  Take for instance the Iris Nebula.  The bright part is only about 18 arc minutes in diameter, or about 1/3 the size of a full moon.  What surrounds it, however is just as interesting.  This image shows more of the dust that belongs to the Iris, but just isnt lit up like the bright part.

It takes a larger number of exposures to be able to see the unlit dust, as it is extremely faint, but I was able to image it rather well in this composite of 24 - 5 minute frames.

New stars form from within dust clouds, and that is what is lighting up the bright part of the Iris.  You can see the light taper off as you move away from the bright stars in the center of the lit area.