A sunspot appears as an
unblinking eye in this close-up view of the surface of the Sun.
Spanning an area three
times wider than the Earth – or about 25,190 miles (40,630 kilometers) –
sunspot AR 10805 appears in this stunning detailed image taken by the Dunn
Solar Telescope in Sunspot, New Mexico.
Sunspots are regions of
surface gas that are cooler than the solar material surrounding them. Their
temperatures range between 6,300 and 10,000 degrees Fahrenheit (3,500 and 5,500
degrees Celsius), and they appear dark when seen against the rest of the Sun.
Astronomers used an
adaptive optics system to compile this sunspot view. Adaptive optics allows
ground-based telescopes to adjust their mirrors repeatedly during an
observation to cancel out the blurring effect of Earth’s atmosphere.
Details like AR 10805’s
sunspot penumbra, which appear as fluted structures radiating out from the
sunspot, as well as penumbral grains and fibrils can easily be seen in this
image. Such features are key to understanding the
magnetic structure of sunspots. The presence of small-scale magnetic flux tubes
is indicated by bright G-band points near the sunspot and between several
granules.
Astronomers used the Dunn
telescope’s AO76 adaptive optics system and Dalsa 4M30 CCD camera to build this image from 80 observations,
each 1/100th of a second long, taken over a period of three seconds.
-- SPACE.com Staff
Credit: Friedrich Woeger, KIS, and
Chris Berst and Mark Komsa,
NSO/AURA/NSF.
