charles 2009-3-23 11:39
太陽表面上的海嘯
A Large Tsunami Shock Wave on the Sun
[img=640,446]http://i10.tinypic.com/30iways.gif[/img]
影像版權: NSO/AURA/NSF and USAF Research Laboratory
[color=navy]Explanation:[/color]
[color=dimgray] Tsunamis this large don't happen on Earth. One month ago, a large solar flare from an Earth-sized sunspot produced a tsunami-type shock wave that was spectacular even for the Sun. Pictured above, the tsunami wave was captured moving out from active region AR 10930 by the Optical Solar Patrol Network (OSPAN) telescope in New Mexico, USA. The resulting shock wave, known technically as a Moreton wave, compressed and heated up gasses including hydrogen in the photosphere of the Sun, causing a momentarily brighter glow. The above image was taken in a very specific red color emitted exclusively by hydrogen gas. The rampaging tsunami took out some active filaments on the Sun, although many re-established themselves later. The solar tsunami spread at nearly one million kilometers per hour, and circled the entire Sun in a matter of minutes.
[color=navy]說明:[/color]
地球上從未發生過的大海嘯。一個月前，一個從地球大小般的太陽黑子發出的閃焰產生了海嘯般的震波。如上圖，在美國新墨西哥洲的光學太陽巡天網(Optical Solar Patrol Network, OSPAN)觀測到這個震波從太陽活躍區 AR 10930 向外擴散時的影像。這個震波，或稱為莫爾頓波，會使太陽光球層裡的氣體，包括氫氣，加熱並壓縮，接著發出強光。上圖是用氫原子發射的特殊紅光 (編按：H-alpha) 波段拍攝的 。這次海嘯般的衝擊也產生了一些活躍的細絲，不過大多數在不久後就復原了。這次日嘯傳播的速度約是每小時一百萬公里，在幾分鐘內便環繞太陽一圈。[/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][size=1][color=white]
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