The Milky Way in Sagittarius

July 30, 2010

MilkyWayfromWilloughbyLakeVt

Photographer: Donald Collins; Don's Website - Physics Photo of the Week
Summary Author: Donald Collins

Clear, dark skies during summer in the Northern Hemisphere reveal the magnificent Milky Way, our gigantic spiral galaxy. We see it as a “river of milk” because we're looking through the plane of the galactic disk. The Sun is just one of about 100 billion stars in our galaxy. As featured here, the constellation Sagittarius is visible, recognizable by its “Teapot” asterism. Look for it just above Mount Hor, the flat-topped mountain overlooking Lake Willoughby, Vermont. The brightest part of the Milky Way in Sagittarius is the region of the galactic center or core of the Milky Way. This central core of stars isn't visible with ordinary cameras or optical telescopes because there's simply too much interstellar dust in the way. Notice the dark lanes scattered through the image. Especially noteworthy is the large dark nebula to the right (west) of the main brightness. This dark nebula is called the “Dark Horse” nebula. The body of the horse is vertical with the horse’s head at the top. Dark nebulae consist of interstellar dust clouds that block the light from background stars. At right in the image is the constellation Scorpio; dominated by the bright star Antares. Photo taken on July 11, 2010.

Photo details:  Canon XTi camera; ISO 1600; Focal length 18 mm; f/4.0; 10 images of 30 seconds exposure stacked and aligned with Maxim DL astronomical imaging software.