Here's one ornament you won't find on a Christmas tree. It's

the Hubble Space Telescope's view of a globular cluster known as M13, located

about 25,0000 light years away in the constellation Hercules. About 100,000

stars live in M13, New York-style, which is to say with little elbow room. At

the core of the cluster, stars are packed together about 100 times tighter than

stars in the neighborhood of our sun. 

"These stars are so crowded that they can, at times,

slam into each other and even form a new star, called a 'blue straggler, "

writes NASA in a press release.

The brightest reddish stars in the cluster are ancient red

giants, which have expanded to many times their original size and cooled. The

blue-white stars are the hottest in the cluster. 

There are about 150 known globular clusters surrounding the

Milky Way galaxy and M13 is one of the brightest and best known.

"The clusters are very old and probably formed before

the disk of our Milky Way, so they are older than nearly all other stars in our

galaxy," writes NASA.

This image is a composite of archival Hubble data taken with

the Wide Field Planetary Camera 2 and the Advanced Camera for Surveys. Credit:

NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgment: C. Bailyn

(Yale University), W. Lewin (Massachusetts Institute of Technology), A.

Sarajedini (University of Florida), and W. van Altena (Yale University).