国家地理 浴火重生的行星（在线收听）

Like a phoenix rising from the ashes, astronomers have found a whole new solar system may be forming in the wake of a star's violent death.

宇航员发现了一个全新的太阳系可能在某颗恒星轰轰烈烈的消亡后形成了，犹如凤凰涅槃一般。

This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.

这是神秘宇宙斯皮策空间望远镜的发现，这个望远镜是罗伯特·赫尔特用来探索红外天文学奥秘的利器。

When a massive star reaches the end of the line, it does not go gentle into that good night. It becomes a supernova, an explosion so bright that it briefly outshines everything else in the galaxy. Most of the heavy elements that make up planets, and even people, are forged in the nuclear furnaces of such explosions. Here we see heavy elements in the Cassiopeia A supernova remnant blowing back into the galaxy and mingling with interstellar gases. The next generation of baby stars forms from this material now enriched with building blocks for growing new solar systems and planets.

每当质量巨大的恒星即将消亡之际，一定会轰轰烈烈地结束，也就是所谓的超新星现象。超新星是一种爆炸的现象，场景极其明亮，亮过了星系里的任何其他事物。组成行星的重元素甚至是人类都是在超新星爆炸的核反应堆里形成的。这里我们可以看到仙后座A源超新星的重元素残留物滚动到了星系中，与星际气体融为一团。而下一颗恒星就是从这团物质中形成的，因为这团物质具备了产生新太阳系和行星的基本元素。

But what of the star that went supernova? Its core still remains in the form of a pulsar. This stellar corpse is tiny and dense, squeezing about 1.5 times the mass of the Sun into an object a mere 10 miles across.

那发生超新星的恒星去了哪里呢？它的内核依然以脉冲星的形式存在着。它的残留物又小、密度又高，是太阳质量的近1.5倍，成了直径10英里的物体。

A team led by Dr. Deepto Chakrabarty at the Massachusetts Institute of Technology has found that even a dead pulsar might play host to a whole new generation of planet formation. They studied a once-massive star that went supernova about 100,000 years ago. In the process it likely wiped out any existing planets. While most of the star-stuff blew off into space, a little bit fell back under the pull of gravity. Dr. Chakrabarty explains. If the original massive star was spinning fast enough then that material won't fall directly back onto the neutron star, but may instead form a disk, and so what we think we've found is a disk of this debris material that's left over from the explosion that formed the neutron star.

麻省理工学院查克拉巴蒂牵头的一个小组发现，脉冲星即便消亡，也会对下一代行星的形成发挥关键作用。他们研究了一颗近10万年前发生超新星的恒星，这颗恒星在消亡前质量很大。在这个过程中，它很有可能导致当时存在的行星灭迹。虽然大部分恒星都飞向宇宙之中，但还有少部分在引力的作用下落下。查克拉巴蒂表示，如果那颗质量超大的原始恒星转速足够快的话，那么其残留物就不会直接落回中子星上，反而会形成一个圆盘，所以我们认为发现的是一个残骸物质组成的圆盘，而这些残骸是爆炸后遗留的，它们最终形成了中子星。

This disk has about 10 times the Earth's mass and looks very much like ones that produce planets around young stars. Moreover, it may help solve a recent planet-making mystery. In 1992, astronomers found the first planets outside our solar system, which were orbiting an older pulsar. But where did they come from? Could they have formed after their star went supernova? The discovery of a planet forming disk around a younger pulsar makes this likely. It seems new planets can arise from the ashes of their own star's death.

这个圆盘的质量是地球的近10倍，看起来很像在年轻恒星附近产生行星的圆盘。而且，这种圆盘或许可以助力解决最近一个有关行星产生的谜题。1992年，天文学家首次发现太阳系外的一些行星，它们都在围绕一个年纪更大的脉冲星飞行。但它们是从何而来呢？它们是在恒星发生超新星后形成的吗？在我们发现某行星在年级更小的脉冲星附近形成圆盘后，就更加确信了这一点。似乎新行星可以从原来恒星消亡的残骸中重生。

However pulsar planets are pretty hostile real estate for life. Pulsars provide little light or heat and would bathe these worlds in intense radiation. A nuclear waste dump at the South Pole might actually be a little more pleasant.

不过，脉冲行星的环境很不适合生命存在。脉冲星上几乎没有阳光和热量，到处都是强辐射。南极的核垃圾站可能都比脉冲星好些。