Multiwavelength extreme ultraviolet image of the Sun taken by the Solar Dynamics Observatory’s Atmospheric Imaging Assembly. Colours represent different gas temperatures: ~800,000 Kelvin (blue), ~1.3 million K (green), and ~2 million K (red). New observations reveal jets of hot plasma propelled upwards from the region immediately above the Sun’s surface. Image: Bart De Pontieu)
The mystery of the Sun’s corona may finally be solved. For years researchers have known – and wondered why – that the Sun’s outer atmosphere, or corona, is considerably hotter than its surface. But now, using the combined visual powers of NASA’s Solar Dynamics Observatory and Japan’s Hinode satellite, scientists have made direct observations of jets of plasma shooting off the Sun’s surface, heating the corona to millions of degrees. The existence of these small, narrow jets of plasma, called spicules has long been known, but they had never been directly studied before and were thought to be too cool to have any appreciable heating effect. But a good look with new “eyes” reveals a new kind of spicule that moves energy from the Sun’s interior to create its hot outer atmosphere.
“Heating of spicules to millions of degrees has never been directly observed, so their role in coronal heating had been dismissed as unlikely,” says Bart De Pontieu, the lead author and a solar physicist at LMSAL.
(…) Read the rest of Previously Unseen Super-Hot Plasma Jets Heat the Sun’s Corona (437 words)
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(C) nancy for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us Post
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