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The reason we can be reasonably confident that such an event won't happen in our corner of the galaxy, Thorstensen said, is that it takes a particular kind of star to make a supernova in the first place.
索爾斯坦森說，有理由相信，這種事情在星系的我們這個角落里不會發(fā)生，這是因為，首先，形成一顆超新星要有一種特別的恒星。
A candidate star must be ten to twenty times as massive as our own Sun and "we don't have anything of the requisite size that's that close. The universe is a mercifully big place." The nearest likely candidate he added, is Betelgeuse, whose various sputterings have for years suggested that something interestingly unstable is going on there. But Betelgeuse is fifty thousand light-years away.
恒星非得要有我們的太陽10-20倍那么大小才有資格，而"我們附近沒有任何符合這個條件的星球"。非常運氣，宇宙是個大地方。他接著說，離我們最近的、很可能有資格的，是獵戶座；多年來，它一直在噴出各種東西，表明那里不大穩(wěn)定，引起了大家的注意。但是，獵戶座離我們有5萬光年之遠。
Only half a dozen times in recorded history have supernovae been close enough to be visible to the naked eye. One was a blast in 1054 that created the Crab Nebula. Another, in 1604, made a star bright enough to be seen during the day for over three weeks. The most recent was in 1987, when a supernova flared in a zone of the cosmos known as the Large Magellanic Cloud, but that was only barely visible and only in the southern hemisphere—and it was a comfortably safe 169,000 light-years away.
在有記載的歷史上，只有五六次超新星是近到肉眼看得見的。一次是1054年的爆炸，形成了蟹狀星云。另一次是在1604年，創(chuàng)造了一顆亮得在3個多星期里連在白天都看得見的恒星。最近一次是在1987年，有一顆超新星在宇宙一個名叫大麥哲倫云的區(qū)域閃了一下，然而僅僅勉強看得見，而且僅僅在南半球看得見--它在16.9萬光年以外，對我們毫無危險。
