M42 The Great Orion Nebula

 (Click here for full sized image)

Emission Nebula

Magnitude 3.0

Size: 85' x 60'

Constellation: Orion

RA: 5h 35.3m

Dec: -5° 23'

 The large glowing object in this photograph is the Great Nebula in Orion. Also known as M42, this nebula and its smaller companion to the north, M43, were cataloged by the 18th century comet hunter, Charles Messier. These nebulas are fluorescent clouds of hydrogen gas and dust excited by the ultraviolet-rich light of nearby blue-hot stars.

M42 is about 26 light-years across, and is located only 1625 light years from us. It is practically in our own celestial backyard.

From a moderately dark site, M42 can be seen with the naked eye as a misty patch of light in the sword of Orion. Beautiful in binoculars, this bright nebula explodes with detail in amateur-sized telescopes.

This image was Santa Barbara Instrument Group's "Image of the Month" for February 2001

Imaging Equipment:

• Telescope: Takahashi FSQ-106N f/5 4-element fluorite refractor
• Zeiss II German Equatorial Mount
• Santa Barbara Instrument Group ST-8E NABG CCD camera (1530 x 1020 pixels, 9 x 9mm, monochromatic, 16 bit, 13.8 x 9.2mm array)
• CWF8 color filter wheel with IR-blocking red, green and blue dichroic filters

Exposure Information:

• Date: Saturday, November 25, 2000
• Location: Joshua Tree National Park, CA
• Elevation: Approx. 3500', OAT +37F.
• Total exposure time: 60 minutes. (4x5 minutes red, 4x5 min. green, and 4x5 min blue)
• Color Stacking: Green luminance behind RGB tricolor image. 60 minutes of deep red, Hydrogen-alpha filtered exposure was shot but not used in final composition. (I felt the green channel had better contrast and produced a more interesting composition than I could achieve with the H-a luminance data.)
• Processing: Dark and flat cal, mean (not median) combining and DDP (on luminance) with MaxIm. LRGB stacking, final level adjustments, color balance, blooming repairs/reconstruction, crop and security with Photoshop.

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