Another in my occasional series of astrophotographs.
Here's a description of the objects:
This photo cotains three Messier objects: Toward the top is the Trifid Nebula, M20; toward the bottom is the much larger Lagoon Nebula, M8, and the open star cluster M21 is to the left of the Trifid Nebula. The Trifid Nebula is so called because it appears to have three lobes in the reddish part. This is a star-forming region, which includes an emission nebula (the reddish part), reflection nebula (blue part) and dark nebulae (the dark parts that appear to divide the emission nebula). The Trifid Nebula is approximately 5,200 light years from us, about 40 light years across, and glows brightly at an apparent magnitude of 6.3 (meaning possibly visible to the naked eye in the very darkest skies). The Lagoon Nebula is a large, bright (magnitude 6.0) emission nebula, also a star-forming region. The Lagoon Nebula is about 5,000 light years from us, and over 100 light years across. The cluster of bright stars directly to the left of the Trifid Nebula is the open cluster M21. The fainter nebulosity to the left of the bright Lagoon Nebula is NGC6559, itself an emission nebula/star-forming region.
I have presented it two ways: First, a color image, then same framing taken entirely through a very narrow-pass filter (a hydrogen-alpha filter, passing a tiny part of the red spectrum; light in this wavelength is the dominant light emitted by the red emission nebulae). These images represent a total of 35 hours of light exposure time (i.e., not including dark frames and flat fields taken for calibration purposes), through five different filters, over innumerable night across over four months. My camera is a Santa Barbara Instruments Group STL110000M; my "lens" is a Takahashi FSQ106 quadruplet fluorite refractor, sitting atop a Software Bisque Paramount ME robotic mount. All this equipment sits in the South Australia desert, while I sit in Seattle.
I love the color picture. It contains an impressive amount of detail and is rich and real. I wish we as humans would be able to look up into the sky and see the universe around us without heavy machinery.
