Physics Photo of the Week

September 7, 2007

The Milky Way Sagittarius Region
Get away from bright city lights and you get to the "bright lights" of the Milky Way.  This view, photographed in northeastern Vermont in July 2007, looks south towards the center of our galaxy.

What we see in the Milky Way are millions of stars, so distant and so numerous that they appear to be merged into a continuous "cloud" of stars.  In addition to the cloud of stars, we can see clouds of interstellar dust blocking some of the starlight.  In fact, we cannot see the center of our galaxy due to the interstellar dust.  Radio astronomy has detected emission from the center of our galaxy near the center of this photo.  Please see the PPOW for November 11, 2005 for a photo of a distant galaxy that shows the dust.

Sagittarius appears as a "Teapot" asterism outlined in the image at right.  Scorpius, "the Scorpion" is also outlined.  The bright red star Antares is easily visible.  Scorpius is being visited this year by the planet Jupiter.  Next year (2008) Jupiter will be close to the Teapot.  At the latitudes where this photo was made, 45 deg N, the horizon and mountains hide part of the tail of the scorpion.  At Warren Wilson (35 deg N) all of the scorpion is visible.

Dark skies are disappearing from many parts of the world due to increasing light pollution from city lights.  The ability to see the stars, planets, and Milky Way should be a right for all world citizens.  Most outdoor lighting wastes much light into the sky, wastes energy, and is surprisingly ineffective for outdoor illumination.  With care, outdoor lighting systems can be designed with shields and reflectors to concentrate the light onto the ground, minimizing the light cast into the sky, use less power, and allow the astronomical objects to be viewed from properly lit urban areas.

Photo details.  The image was made with a Canon A360 digital camera set at an ISO rating of 800.  20 images of 15 seconds each were aligned and co-added using MaximDL software.  The contrast and color saturation was enhanced to show the highly colorful region.




Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department.  These photos feature an interesting phenomena in the world around us.  Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation.  Atmospheric phenomena are especially welcome.  Please send any photos to dcollins@warren-wilson.edu.


Click here to see the Physics Photo of the Week Archive.

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