Russell Croman took this
amazing image of the Orion Nebula last month from his backyard observatory in
Austin, Texas.
Orion is a hotbed of star
formation, the nearest known. It is about 1,500 light-years away in the same
spiral arm of the Milky Way as our solar system.
Croman used a 14-inch telescope,
exposing Orion for 7.5 total hours on two nights. Hey employs specialized filters
that isolate light from distant objects while rejecting unwanted urban and suburban
light.
"In the case of this image,
three filters were used, isolating specific colors of light produced by the
nebula," he explained. "The red, green and blue channels of the image were assigned
to wavelengths emitted by sulfur, hydrogen and oxygen, respectively."
Separate images were collected
digitally with the help of specialized software called MaxIm DL, which controls
the camera and calibrates the data. Then he assembled them using the popular
program Photoshop. The final product highlights colors to a greater extent than
what a true-color image would show, thereby enhancing Orion's interesting features,
mostly hydrogen gas and dust being blown about by strong particle winds and
radiation from massive, hot stars.
The photographic process
is similar to what's done to produce pictures from the Hubble Space Telescope.
Of course the orbiting observatory is much bigger, with a mirror nearly 8 feet
(2.4 meters) in diameter, and it is above the blurring effects of Earth's atmosphere.
