Explanation:
Visible light images
show the central region of globular
cluster 47
Tucanae is closely packed, with stars
less than a tenth of a light-year apart.
This Chandra false-color
x-ray view
of central 47 Tuc also shows the
cluster is a popular neighborhood for
x-ray stars,
many of which are "normal" stars
co-orbiting with extremely dense
neutron stars
-- stars with the mass of the Sun but
the diameter of Manhattan Island.
One of the most remarkable of these exotic
binary systems is
cataloged as 47 Tuc W, a bright source
near
the center of this image.
The system consists of a low mass star and a
a neutron star that spins once every 2.35
milliseconds.
Such neutron stars are known to radio astronomers
as millisecond pulsars, believed to be driven to such
rapid rotation by material falling from the normal star onto
its dense companion.
In fact, x-ray observations of the 47 Tuc W system
link this
spin-up mechanism observed to operate in other x-ray binary
stars with fast rotating millisecond
pulsars.
