The "Great Nebula in Orion" can be seen by naked eye as the middle "star" in Orion's dagger. This 4.0 magnitude diffuse nebula is at a distance of 1,600 light years, and spans a full degree of sky (twice the size of the full moon). It is a reflection nebula aglow from the new stars being formed within. It is also known as NGC 1976.
The image below was taken during a total lunar eclipse in order to get the color data. Otherwise the full moon is too intense.
The image above was taken with the ST-8E camera at f/5 on the FSQ 106N and AP900 from Mistletoe Observatory in Monmouth Oregon Feb 20, 2008. It is an HaRGB composite (as detailed below) with a total exposure time of 69 min. Calibration and alignment were done in MaxIm DL. Ha was used as a 50% luminance mix. Final processing was done with Photoshop.
|HA||45 min||15 x 3 min||1x1|
|Red||6 min||6 x 1 min||1x1|
|Green||6 min||6 x 1 min||1x1|
|Blue||12 min||6 x 2 min||1x1|
Below is the previous version taken on Jan 3 2000.
This image is a mosaic of two areas. M43 is in the top 25%, and M42 makes up the bottom 75%. The larger M42 area is a median of 20 images of 2 seconds each. The M43 part is a median of 10 images each of 2 seconds each. Look closely and you can see a faint herringbone pattern in the top part due to poorer signal to noise in only 10 exposure verses 20.
Also, I learned that taking only a few dark frames actually adds noise in this situation. The relatively noisy darks are combined with each of the individual data frames. The final image here was not processed with any darks.
The raw frames were taken with the 12" LX200 at f3.3 and
the 416XT CCD at Fremont Peak, CA. on Jan 3, 2000.
Below was my previous "best", taken Feb 19, 1999. Since it was only a single exposure, it is much noisier than I like.
A single 5 second exposure taken with the 12" LX200 and 416XT CCD at f3.3 in Monmouth, OR.
The 4 stars to the left (known as "the trapizium") are a subimage from the center of the main picture with a different brightness setting.