NASA discovery May 14th----Rebate Check = Lovely Parting gift =going away present?

news
[link to www.nasa.gov]

"Some of the oldest objects in the Universe may still have a long way to go, according to a new study using NASA's Chandra X-ray Observatory. These new results indicate that globular clusters might be surprisingly less mature in their development than previously thought.

Globular clusters, dense bunches of up to millions of stars found in all galaxies, are among the oldest known objects in the Universe, with most estimates of their ages ranging from 9 to 13 billions of years old. As such they contain some of the first stars to form in a galaxy, and understanding their evolution is critical to understanding the evolution of galaxies.

"For many years, globular clusters have been used as wonderful natural laboratories to study the evolution and interaction of stars," said John Fregeau of Northwestern University, who conducted the study. "So, it's exciting to discover something that may be new and fundamental about the way they evolve.


For years, it has been thought that most globular clusters are middle-aged with a few being toward the end of their evolution. However, Chandra data along with theoretical work suggest this may not be the case

It's remarkable that these objects, which are thought to be some of the oldest in the Universe, may really be very immature," said Fregeau, whose paper appears in The Astrophysical Journal. "This would represent a major change in thinking about the current evolutionary status of globular clusters

If confirmed, this result would help reconcile other observations with recent theoretical work that suggest the tightness of the central concentration of stars in the most evolved globular clusters is consistent with them being in a middle, rather than an advanced phase of evolution. Other theoretical studies have suggested it can take longer than the current age of the Universe for globular clusters to reach old age.

Besides improving the understanding of the basic evolution of globular clusters, this result has implications for understanding stellar interactions in dense environments. It also removes the need for exotic mechanisms - some involving black holes - that were thought to be needed to prevent the many middle-aged clusters from collapsing"