本帖最后由 suhuasky 于 2013-1-12 12:07 编辑
COMET ISON APPROACHES: Later this year, Comet ISON could put on an unforgettable display as it plunges toward the sun for a fiery encounter likely to turn the "dirty snowball" into a naked-eye object in broad daylight. At the moment, however, it doesn't look like much. John Chumack sends this picture, taken Jan. 8th, from his private observatory in Yellow Springs, Ohio:
"Comet ISON (C/2012 S1) is currently in the constellation Gemini, moving between the heads of the twins Castor and Pollux," says Chumack. "It is still pretty faint, near 16th magnitude, but don't be fooled by that. This could become one of the best comets in many years." Comet ISON is a sungrazer. On Nov. 28, 2013, it will fly through the sun's outer atmosphere only 1.2 million km from the stellar surface below. If the comet survives the encounter, it could emerge glowing as brightly as the Moon, visible near the sun in the blue daylight sky. The comet's dusty tail stretching into the night would create a worldwide sensation. Comet ISON looks so puny now because it is so far away, currently near the orbit of Jupiter. As it falls toward the sun in the months ahead it will warm up and reveal more about its true character. By the summer of 2013, researchers should know whether optimistic predictions about Comet ISON are justified. Possibilities range from " Comet of the Century" to disintegrated dud. Stay tuned! 今年晚些时候,彗星ISON将呈现出令人难忘的景象,这个脏雪球靠近火热的太阳并且成为一个白昼肉眼目标,目前它看起来并不起眼。John Chumack发送了这张照片,这是他1月8日从俄亥俄州耶洛斯普林斯的私人天文台拍摄的:“彗星 ISON (C/2012 S1)目前位于双子座,在双胞胎北河二和北河三之间移动”,Chumack说。“它仍然是非常微弱的,接近16等亮度,但是不要被欺骗了,这可能是很多年以来最壮丽的彗星之一。”
ISON是颗掠日彗星,2013年11月28日,他将从离表面仅120万公里飞过太阳的外层大气,如果彗星能够生存,它将到达超过满月的亮度,在白昼蓝色的天空可以在太阳附近看到。彗星的尘尾将在夜空中伸展并造成全球性轰动。
ISON彗星看起来很弱小是因为现在还很遥远,目前在木星轨道附近。未来几个月它在落向太阳中被加热并展示出它的本质。到2013年夏天,研究者能够知道对ISON彗星乐观的预测是否合理。有可能成为“世纪彗星”或者破裂解体成为哑弹,敬请期待。
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