A Large Tsunami Shock Wave on the Sun
Image Credit: NSO/AURA/NSF and USAF Research Laboratory
Explanation: Tsunamis this large don’t happen on Earth. During 2006, a large solar flare from an Earth-sized sunspot produced a tsunami-type shock wave that was spectacular even for the Sun. Pictured here, 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 featured 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.
Tomorrow’s picture: andromeda now and again
影像提供: NSO/AURA/NSF and USAF Research Laboratory
说明: 地球上从未发生过这么大的海啸。在2006年，一个大小与地球相近的太阳黑子发出强烈闪焰，并触发了对太阳来说也是很壮观的海啸般震波。如这幅由位在美国．新墨西哥洲的光学太阳巡天网（OSPAN）拍摄之影像所示，这例海啸波从太阳活跃区AR 10930 向外扩张。这种名为莫尔顿波的震波，压缩并加热太阳光球层里包括氢在内的气体，太阳因而短暂发出更明亮的辉光。上图系摄于氢原子发光的特殊红光波段。这次海啸般的冲击波也消灭了一些活跃的暗条，不过有些后来又重建复现。此例太阳海啸在几分钟之内就绕行太阳一圈，传播的速度大约是每小时1百万公里。
明日的图片: andromeda now and again