The bubbling, roiling surface of the sun has been imaged in
unprecedented detail, shedding light on the processes at work on the solar
surface.
Images of transient dark
spots, the sun's seemingly granulated texture and moving packets of gas
were snapped by the SUNRISE
balloon-borne telescope.
SUNRISE, the largest solar telescope ever to have left Earth
was launched from the ESRANGE Space Centre in Kiruna, northern Sweden, on June 8. The 6-ton telescope is dangling from a gigantic helium balloon with a
diameter of 427 feet (130 meters).
After launch, SUNRISE reached a cruising altitude of 37 km
above the Earth's surface. At this height, the telescope is in a layer of the
Earth's atmosphere (the stratosphere) with observing conditions similar to
those from space. Air turbulence isn't a factor for SUNRISE as it is for
telescopes on the ground, and ultraviolet light from the sun can be viewed,
which would be blocked out by ozone at the surface.
During its five-day flight, SUNRISE gathered 1.8 terabytes
of observation data. Scientists have only just begun analyzing the data, though
the first findings are already promising.
Of particular interest to astronomers is the connection
between the strength of the sun's
magnetic field and the brightness of tiny magnetic structures on its
surface. Since the magnetic field varies in an 11-year
cycle of activity, the increased presence of these foundational elements
brings a rise in overall solar brightness, resulting in greater heat input to
the Earth.
The variations in solar radiation are particularly
pronounced in ultraviolet light. During its stratospheric flight, SUNRISE carried out the first-ever study of the bright magnetic structures on the solar
surface in this important range of the sun's spectrum. Previously these
structures could only be studied by computer model representations.
"Thanks to its excellent optical quality, the SUFI
instrument was able to depict the very small magnetic structures with high
intensity contrast, while the IMaX instrument simultaneously recorded the
magnetic field and the flow velocity of the hot gas in these structures and
their environment," said Achim Gandorfer, project scientist for SUNRISE at
the Max Planck Institute for Solar System Research in Germany.
After completing its mission and separating from its balloon,
SUNRISE parachuted safely down to Earth on June 14, landing on Somerset
Island, a large island in Canada's Nunavut Territory situated in the Northwest
Passage, the seaway through the Arctic Ocean between the Atlantic and the
Pacific.
SUNRISE is a collaborative project between the Max Planck
Institute for Solar System Research in Katlenburg-Lindau and partners in Germany, Spain and the United States.
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