Oddities of Star Cluster NGC 6397
Explanation:
One of these stars is blinking.
This star, a member of
globular cluster NGC 6397,
is noteworthy not just because it blinks, but because it
blinks so fast and because its companion star is so atypical.
Speculation holds that this might be a
neutron star spun up to a rate of 274 rotations
each second by the
bloated red star it orbits.
Matter gravitationally pulled from the bloated star likely
orbits the
millisecond pulsar, making it spin faster when it crashes onto the surface.
The odd system might have resulted when the
neutron star
captured a normal star after a near collision near the
globular cluster's dense center.
Other collisions near the center of
NGC 6397 are thought
to have produced other oddities --
blue straggler stars.
The
Hubble Space Telescope
took the
above image of the colorful
globular cluster.
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.
