Spiral Sunspot
Explanation:
Spiral galaxies
abound in the universe, but spiral
sunspots are definitely an unusual twist.
This distinctive spiral-shaped sunspot caught the attention of
National Solar Observatory astronomers and was photographed
on February 19, 1982 with the
Vacuum Solar Telescope on Kitt Peak.
Sunspots
appear dark only because they are relatively cool -
about 4,000 degrees compared to the 6,000
degrees Celsius
of the surrounding solar surface.
Associated with surface magnetic fields,
their numbers increase and decrease in a regular pattern tracing
the Solar Activity cycle.
A maximum in
sunspot numbers occurs every 11 years with the
next maximum expected around the year 2001.
This
sunspot was
actually about 50,000 miles across (Earth's diameter
is about 8,000 miles) and held its shape for two days.
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.
