Like cosmic
rubber bands, twisted magnetic structures along the Sun's surface can release massive
amounts of energy when relaxed. The discharge could be the "hidden" source that
heats up the atmosphere of the Sun.
The
findings, presented today at a NASA Space Science Update in Washington D.C., come from images taken by the X-ray telescope (XRT) aboard the Japan Aerospace Exploration
Agency's satellite, Hinode. Formerly known as Solar-B,
Hinode (Japanese for "sunrise") was launched on Sept. 22, 2006 on a three-year
mission to study the Sun.
While the Sun's
surface is a steamy 10,000 degrees Fahrenheit (5,538 degrees Celsius), gas
floating above in the so-called corona
soars to more than 100 times hotter. Astronomers have long puzzled over the
source of the corona's heat.
Hinode's
telescope imaged the million-degree gas spiraling up from sunspots
as well as the corona gas in the Sun's
atmosphere. The pictures revealed twisted and tangled magnetic fields that
could give this hot outer layer a jolt of heat. The arcing magnetic structures
store huge amounts of energy, which they can release when they unwind into
simpler configurations. The astronomers suggest the released energy heats up
the corona and powers solar
eruptions and coronal
mass ejections.
"Theorists
suggested that twisted, tangled magnetic fields might exist," said study
presenter Leon Golub, senior astrophysicist at the Harvard-Smithsonian Center for Astrophysics. "With the XRT, we can see them clearly for the first time."
Along with
the X-ray telescope aboard Hinode, the Solar Optical Telescope (SOT) will
provide images of features on the Sun's surface, while the Extreme Ultraviolet
Imaging Spectrometer (EIS) can track charged solar material as it moves around.
Together the trio is expected to help astronomers understand and forecast solar
flares and other types of space weather.
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