Globular Clusters May Have a Long Way to Go
May 6, 2008 -- Once thought to be approaching their twilight years, new research at NASA's Chandra X-ray Observatory suggests that many globular star clusters may be earlier in their development than previously thought.
Globular clusters are spherical concentrations of stars that orbit a galactic core, and they are believed to contain some of the first stars produced in a galaxy. The relative maturity of these objects is estimated based on the radiation emitted from their dense centers. When stars interact in close proximity, they sometimes form binary stars, two stars orbiting each other that emit X-ray radiation. The number of X-ray sources in a globular cluster's center corresponds to the center's density, which can be applied to current models to estimate its stage in life.
The recent observations at Chandra suggest that clusters previously thought to be reaching old age are actually earlier along in their evolutionary life cycle. This result would agree with recent theoretical work that suggests that the time it takes for globular clusters to reach maturity is longer than the current age of the universe.
These discoveries were made using high-resolution X-ray observation, which the recent National Research Council report NASA's Beyond Einstein Program: An Architecture for Implementation identifies as an area that is ripe for further exploration. Another report, Portals to the Universe: The NASA Astronomy Science Centers, concludes that the current set of centers -- including the Chandra Observatory Center -- have sufficient scientific and programmatic expertise to manage NASA’s astronomy center responsibilities at present, but it stresses the importance of attracting and retaining individuals with the right mix of research and engineering skills necessary to maintain continuity of service.