还有一个讲超新星的，貌似看过JJ，求大家考古一下，但是实在想不起来了 第一段首句是所有的行星最后都会变成超新星（这个我记得很清楚），然后讲了一大堆专业术语，第二段忘了 -- by 会员 沙漠之狐沉雨 (2011/10/27 16:47:02)
请问楼主，超新星那篇，是上月太阳起源那篇么？
23、**太阳起源
文章：
（太阳的产生不是孤立的，而是一系列超新星爆炸的产物）
1.科学家在陨石上发现一些矿物，可以证明太阳在新生时曾与一supernova非常接近。进而推测太阳是从cluster explosion中产生的，而非像现在一样远离其它galaxies。
2.Nickel从Iron60衰变而来（根据背景材料推测，Iron只能来自Supernova的爆炸）。（推测应该是离太阳five light years远的Supernova爆炸）
3.离中心越远，Heavy element越少。如果太阳had been Secluded，就不会有这些物质（Nickel和Iron60）。证明1
4.Comet的轨道很奇怪，作者解释是被其他一些类似太阳的星球带的。再次证明1.
5.科学家（宇航员）正在太阳多少范围内的arc上寻找有没有别的太阳一样的星星。若有，他们应该和太阳一样受到那个爆炸的超新星的物质辐射。
题目：
1.细节题 Nickel60和Iron60从哪来的。（Iron一定是从太阳旁边的一个超新星爆炸时候喷到太阳上面来的）；Nicel是从Iron60衰变来的
2.Infer题
3.关于科学家的研究，下面哪项是对的（Iron从太阳以外的地方来，或nickel60是从iron60衰变来的）
4.Comet和Orbit有题。
5.宇航员找到什么会weaken科学家的研究/观察的现象不是这样会出现什么问题。（太阳产生的时候应该是和stars们成一个 cluster，如果找到其他stars，没有Nichel60，那论断就被削弱了/那么太阳和stars就会disperse什么的。）
6.问文章最后一段的作用。（获得更多证据来证实上文观点。）
7.main idea。(证明太阳来自cluster。)
背景知识1：
·The sun is a solitary star, and astronomers have traditionally assumed it formed as such. Yet most stars are born in clusters, and scraps of evidence from meteorites and from the arrangement of comets suggest that our sun was no exception.
·This suggests to Bizzarro and his colleagues that iron-60 was added to the cloud of gas and dust surrounding the primitive Sun (the protoplanetary原行星盘 disk) about 1 million years after the Solar System formed. This could happen if the Sun's nursery contained massive stars (perhaps 30 times the mass of the Sun). Such stars last only about 4 million years. They are extremely active, blowing away their outer layers in the last million years of existence. The dispersed material would have included aluminum-26 and might have caused collapse of interstellar星际的 gas and dust to cause formation of the Sun and its protoplanetary disk. A million years later the massive star exploded, ejecting iron-60 from its interior. Bizzarro and colleagues argue that this huge event of destruction and creation is recorded in the meteorites.
背景知识2：
Astronomic observations with the latest and greatest telescopes are leading astronomers to embrace the idea that stars usually form in clusters, even if they end up, like our Sun, isolated from other stars. Cosmochemists using optical microscopes, electron microscopes, and mass spectrometers are finding evidence supporting the idea, along with important details about the star-forming regions and about the earliest history of the Solar System. The latest breakthrough is reported by Martin Bizzarro and his colleagues at the Geological Institute and Geological Museum in Denmark
, at the University of Texas, and at Clemson University in South Carolina. They made high-precision measurements of iron and nickel isotopes. The results show that the oldest planetesimals星子 to form in the solar system did not contain any iron-60 ( 60Fe), which decays to nickel-60 ( 60Ni) with a half-life of only 1.5 million years, yet somewhat younger materials did contain it. In contrast, aluminum-26 ( 26Al), with a half-life of 740,000 years, was relatively uniformly distributed.
The 60Fe cannot have come from a source too far from the infant Sun. If too far away it would decay before arriving or be so diluted that we could not measure it. The exploding star had to be in the Sun's general vicinity. It was a cluster mate of the Sun. One type of massive star is called a Wolf-Rayet star (named after the discoverers). In these large objects, elements formed inside by nuclear fusion, such as oxygen and aluminum, migrate toward the surface. This concentration of material begins to adsorb吸附 light from inside, eventually resulting in strong winds blowing off the surface and into interstellar space. The winds are shown in the image, below, taken in the infrared. Astronomers believe that most massive stars (those >20 times the mass of the Sun) go through a Wolf-Rayet phase, which ends when they explode as supernova.
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楼主
发表于 2011-10-27 20:07:19