Blue Stagglers in Globular Clusters
Explanation:
This old dog is doing new tricks. On the left is ancient
globular cluster
47 Tucanae
which formed many billions of years ago.
On the right is a closeup of its dense stellar center by the
Hubble Space Telescope,
released last week.
Circled are mysterious stars called
"
blue stragglers." Stars as bright and blue as blue stragglers
live short lives, much shorter than the age of the host
globular cluster itself.
But this contradicts evidence that
globular cluster
stars formed all at once.
Although this problem has been known for almost 50 years,
a mass and spin rate for a blue straggler was first
published last Saturday.
This new information indicates that BSS 19 was rejuvenated by
two orbiting stars slowly coalescing ,
and not by a dramatic collision.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
