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Astronomers have observed possibly the biggest blast ever seen in the cosmos. When NASA's SWIFT space observatory first spotted it 10 days ago, observers thought it was a massive star blowing up as a supernova and expected it to fade within hours or even minutes. But the high-energy radiation from the source has shown no sign of dying down, which suggests that astronomers may have caught a star in the process of being ripped to shreds by a black hole. |
天文学家们可能观察到了宇宙间最大的爆炸。十年前美国国家航空航天管理局（NASA）的“雨燕”号太空望远镜首次发现该爆炸的时候，观测人员认为那是一颗大型恒星正在爆炸而形成超新星，他们预计几个小时甚至几分钟之内就会暗淡下来。但是，来自那个爆发源的高能辐射一直没有逐渐消失的迹象，这表明天文学家们所观察到的可能是一颗恒星正在被黑洞撕成碎片的过程。 |
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The blast is actually a series of bursts, like a string of firecrackers going off one after another. "We know of objects in our own galaxy that can produce repeated bursts, but they are thousands to millions of times less powerful than the bursts we are seeing," says Andrew Fruchter of the Space Telescope Science Institute in Baltimore, Maryland. "This is truly extraordinary." |
此次爆炸实际上是一系列的爆发，就像鞭炮一样一个接一个地燃放。“我们了解到银河系的天体可以产生不断地爆炸，但是那些爆炸的威力比我们正在观测到的爆炸威力要小几千倍到几百万倍，”马里兰州巴尔的摩市太空望远镜科学研究院的安德鲁·弗鲁赫特说，“这真是太奇怪了！” |
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SWIFT's Burst Alert Telescope detected the source of the bursts on 28 March. The Hubble Space Telescope took an image of the source on 4 April, which located the explosions at the center of a galaxy 3.8 billion light-years away. On the same day, NASA's Chandra X-ray Observatory took a picture of the source by pointing at it for 4 hours. That image also showed that the source of the bursts was at the center of the galaxy imaged by Hubble. |
“雨燕”号上搭载的爆发警示望远镜探测到3月28日的系列爆发之源。哈勃太空望远镜在4月4日拍到了一张该爆发源的图像，确定了系列爆炸位于38亿光年之外一个星系的中心。同一天，NASA的钱德拉X射线望远镜在四个小时的时间里对准这个爆发源，为其拍下了一张图像。该图像也显示，这个爆发源位于哈勃太空望远镜所拍星系的中心。 |
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The position of the source within the galaxy offered a clue that the bursts might be associated with a black hole, as nearly all galaxies have a black hole in the middle. "We think that there is a dormant black hole there that has accreted a lump of matter—probably a star that has fallen into it," says astrophysicist Neil Gehrels, the lead scientist for SWIFT at NASA's Goddard Space Flight Center in Greenbelt, Maryland. |
位于星系中心位置的爆发源供了一个线索：系列爆发可能跟黑洞有关，因为几乎所有星系的中间都有一个黑洞。“我们认为那里潜伏着一个黑洞，黑洞吸积了大团的物质，这团物质很可能是落入其中的一颗恒星，”马里兰州格林贝尔特市NASA戈达德太空飞行中心的天体物理学家、研究“雨燕”号的首席科学家尼尔·格雷尔斯说。 |
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What could be going on is the following: A star flitting too close to the black hole has been grabbed by its gravitational pull. The star's gas has been falling into the black hole, causing enormous amounts of energy to be released in the form of high-energy particles shooting out like a jet. |
可能发生了如下的情况：一颗恒星飞离那个黑洞太近了，被黑洞的引力捕捉到，恒星的气体不断地落入黑洞之中，引起大量的能量以高能粒子的形式释放出来，射向太空，犹如一股射流。 |
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Although this is not the first time astronomers have witnessed a star being gobbled up by a black hole, the bursts are putting out energy far greater than previously seen. One reason for the extreme brightness could be that the jet of particles shooting out of the black hole is pointing straight at Earth. |
尽管这不是天文学家们首次目击恒星被黑洞吞噬的情况，但是这次的系列爆发正在释放出来的能量比以往所观察到的要大得多。这一系列爆发极度明亮的一个原因可能是，从黑洞射出的射流正在径直地朝着地球的方向而来。 |
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Astronomers all over the world are working round the clock to collect more data on the event, and Hubble is snapping more images of the source. "Some spectra have been taken; there's a lot more work to be done on how the spectrum changes over time," Gehrels says. "If it really is a star being torn up, then we'd expect it to fade away in the next few days. If it stays bright for several weeks or a month, that would tell us something different. I'm not sure what that would be." |
为了更多地搜集该事件的数据资料，全世界的天文学家们正在夜以继日地工作，哈勃太空望远镜正在为这个爆发源拍摄更多的快照。“已经拍到了一些光谱，然而要想弄清光谱是如何随着时间的推移而发生变化的，还有大量的工作要做，”格雷尔斯说，“如果真是一颗正在被撕碎的恒星，那么我们预计它在接下来的几天之内就会逐渐消失；如果持续保持光亮几周或一个月的时间，那么就表明存在不同的情况。我还不能确定这属于什么样的情况。” |
