Sunspot Stack
Explanation:
Welcome to
multiwavelength astronomy!
From top to bottom, these stacked panels show the largest sunspot
group in a decade in visible, extreme ultraviolet, and x-ray light.
All were taken on March 29,
around
the time the famous solar active region,
cataloged as
AR 9393,
was at its peak size -- over 10 times the size of planet Earth.
The panels illustrate how the "appearance" of the active
region changes, when imaged in
electromagnetic radiation (light) of
progressively shorter wavelengths.
In the visible light panel,
dark islands of sunspots stand out against
the bright solar surface, but the situation seems to be reversed in
the extreme ultraviolet panel with a bright active region seen against a
darker background.
Finally, the x-ray panel reveals majestic loops of glowing plasma
arcing far above the sunspot group.
Why do pictures
of the same part
of
the Sun look so different?
Made at different wavelengths, each panel actually records a
different layer in the solar atmosphere.
Top to bottom, the altitude of each layer
(along with temperature) increases; starting with the Sun's visible surface
or
photosphere (about 5 thousand kelvins), then the
chromosphere /
transition
region (ten to a hundred thousand
kelvins),
and finally the
solar corona (millions of kelvins).
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.
