The American Association of Amateur Astronomers
The Constellation Orion - The Hunter
  
One of the most easily recognized of all constellations, Orion lies near to the Milky Way, and thus contains
many open clusters and some of the best nebulae in the heavens. Led by the bright stars Betelgeuse and Rigel, this
constellation holds many fine telescopic and binocular objects, along with some of the most photographed regions
of the sky. Its arrival in the night sky in December signals the beginning of the winter observing season, with
its crisp, clear nights and fine “seeing”. So bundle up, make some coffee or hot chocolate, and get out under the
stars for some of the finest observing of the year!
M42 - The Great Nebula in Orion
 One of the finest sights in the entire sky, M42 is easily visible to the naked eye as the “fuzzy” star
in the middle of Orion’s sword. It appears distinctly nebulous in binoculars or finder scopes, and shows an amazing
amount of detail through the telescope. It is fully a degree in extent, with a wealth of fine curling wisps of
nebulosity curving out from the brightest region surrounding the four relatively bright stars known as the Trapezium.
On good nights with low power, I have even been able to see colors in this object. The region around the Trapezium
appears as a cold steel blue color, while the wispy regions further away can appear as a soft ruddy pink.
Slightly separated from the main nebulosity is M-43. This nebula is seen as a comma shaped cloud surrounding
an eighth magnitude star just north of the Great Nebula. The more time you spend in this area, the more fine detail
you can seen.
 The Trapezium is seen at the core of the Orion Nebula. It appears as a trapezoid, with four bright stars at unequal distances. A closer look will show six distinct stars, and an even closer look will show more. A bluish nebulosity shines throughout this grouping, and a 3 dimensional appearance can be seen under high magnification.
M78
M-78 is another fine area of nebulosity. It is about 6' in diameter, and surrounds two magnitude 10 stars.
It is somewhat fan shaped, and appears comet-like at low powers. NGC's 2064, 2067, and 2071 lie in very close proximity
to M-78, and are all nebulous regions as well.
Other objects to look for in Orion
NGC 1973-75-77 Dubbed the "Running Man" nebula by well-known astrophotographer Jason Ware,
this is a relatively bright region of nebulosity just north of the M-42 complex. It is large, about 15'x10, and
surrounds several relatively bright stars. The "Running Man" is seen as the dark region between the areas
of nebulosity, and often shows up in wide angle photographs of the Great Nebula. It would be observed more often
if it weren't located so close to M-42, and greatly deserves more attention.
NGC 2022 This is a small, but relatively bright planetary nebula about 20" in diameter. It is slightly
brighter at the center, and fades gradually to the edges..
IC 434 - The Horsehead Nebula
Orion provides a nearly impossible object to view optically. It has been done, though. The Horsehead Nebula is an object which shows nicely in photographs, but most observers have never seen it visually. It takes an extremely exceptional night of clear, still air and no Moon. It also takes a fairly large aperture telescope and much patience. If you have the opportunity to view this object, take it, but don’t be disappointed if you don’t see it. It is quite a task.
The "horsehead" can be distinguished quite easily on the right side of
this image, outlined in the red luminosity of the emission nebula.
If you wish to view the Horsehead Nebula yourself, you will need a large
aperture telescope equipped with a narrow band-pass filter especially designed
for viewing emission nebula.
One filter line of note is Lumicon's H-Beta filter. As the name
indicates, the filter only lets through the H-Beta emission line of Hydrogen,
and is mainly useful on a limited number of objects, like the Horsehead Nebula,
the California Nebula, the Coccoon Nebula, and M43. On an 8" to 10"
scope, the Horsehead Nebula goes from invisibility to visibility, as does the
California Nebula. However, these objects remain fairly faint (especially the
Horsehead), and unless you REALLY like looking at them, you can probably forget
about buying the H-Beta!
Much easier to see is the Flame Nebula, which is the
bright area just to the bottom left of the blue star, Zeta Orionis.
Article © Copyright Rick Raasch
Photos © Copyright Edward P. Flaspoehler, Jr.
Messier Objects in Orion
|
Con
|
Messier
|
Type
|
R.A.
|
Dec.
|
Mag.
|
Size
|
NGC#
|
|
Ori
|
M42
|
Diffuse Nebula
|
5h 35.3
|
-5d 23
|
5.0
|
85' X 60'
|
1976
|
|
Ori
|
M43
|
Diffuse Nebula
|
5h 35.5
|
-5d 16
|
7.0
|
20' X 15'
|
1982
|
|
Ori
|
M78
|
Diffuse Nebula
|
5h 46.8
|
0d 4
|
8.0
|
8' X 6'
|
2068
|
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