Physics Photo of the Week

Warren Wilson College

M3 - A globular cluster

Globular clusters are very old associations of stars.  The number of stars in these clusters ofter exceeds 500,000 stars.  These objects slowly orbit the fringes of the Milky Way galaxy and are the most distant objects associated with our galaxy locatable with a small telescope.  M3 is almost 34,000 light years distant.  Compare that with the distance of less than a few hundred light years for most of the naked-eye visible stars.   Because of the large mass of stars, globular clusters are very old and stable star configurations.  It is estimated that M3 is between 5 billion and 10 billion years old.  Because of the extreme age, the more massive stars (the brighter stars which are seen in these photographs) have evolved into red giants.  Notice the preponderance of the red-tinted stars in the image at left using a camera that maintains a good color balance.  For more information, see the SEDS website.

This image was recorded with a digital camera on May 10, 2004.  13 frames of 15 sec each were aligned and co-added to produce a relatively noise-free image

This image was produced using a modified webcam to allow for time exposures on June 6, 2003.  This consists of 21 frames at 20 sec each aligned and co-added as with the image at left. 

Both photographs made by Donald F. Collins.  The digital camera photograph (left) obtains the true color of the stars better than the webcam image on the right.  Both images have been highly enhanced to show the color details.

Click here to see all Physics Photo of the Week for 2004.  Note:  This is the final regular Physics Photo of the Week until the new semester that starts in August, 2004, except for any unusual events.  Meanwhile the Physics Photo of  the Week welcomes any interesting photographs from any members of the college and physics community.  When you see an unusual cloud formation, optics phenomenon, weather event, please send a digital photo to: