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恒星之前世今生

Stars 101 | National Geographic

如静谧夏夜里的萤火虫一般
Like fireflies on a still summer night,
它们轻轻地点亮鸿蒙绵柔的天空
they gently dot and illuminatethe infinite velveteen sky.
恒星科学101
SCIENCE 101 STARS
恒星
Stars.
无论是几百万年还是几十亿年的恒星
Be they millions or billions of years old,
它们都是在尘埃和氢气组成的
are all born in nebulae,
星云中诞生的
clouds of dust and mostly hydrogen gas.
在这些恒星的摇篮中
Within these stellar nurseries
恒星通过尘埃及气体的聚集 坍缩
stars begin life as protostars or hot cores formed
以原恒星核或热核的形式开始生命
by the collection and collapse of dust and gas.
随着原恒星变得越来越热
As the protostars become hotter,
核内的氢核开始聚变
hydrogen nuclei inside ofthe cores begin to fuse
并生成了氦
and create helium.
正是这种化学反应 热核聚变
It is this chemical reaction,thermonuclear fusion
给恒星提供热量和能量
that generates a star’s heat and energy
并使其发光
and causes it to shine.
恒星是根据一些特征来分类的
Stars are categorized by a number of characteristics.
其中一种称为光谱型分类
One of these classificationsis by surface temperature
是根据其表面温度分类
called spectral classes.
共分七大类温度
These seven major groups range
M代表最冷的恒星
from the coolest stars which are designated
从M往上升
as M and up to the hottest stars
O代表最热的恒星
which are designated as O.
恒星还可以根据光量与光度分类
Stars are also classified by the amount of light they emit or luminosity.
称为光度型分类
Called luminosity classes,
光度型又分9大类
these nine major groups range from the small,
从小而不明亮的白矮星
less bright white dwarfs
到大而非常明亮的超巨星
to the large and extremelybright hypergiants.
但不管光度或表面温度如何
But no matter their luminosityor surface temperature,
所有的恒星最终都会随着
all stars eventually burnthrough their hydrogen fuel
氢燃料枯竭而消亡
and die out.
质量较小的恒星 比如
Less massive stars such
太阳会将它的恒星物质释放到太空中
as our sun release their stellar material into space
留下一颗由行星状星云环绕的白矮星
leaving behind a white dwarf surrounded by a planetary nebula.
但质量更大的恒星不会像太阳那样
More massive stars instead blast matter
它们会把物质释放到超新星中
into space in a bright supernova
形成一种密度极高的中子星
leaving behind an extremely dense body called a neutron star.
而质量最大的恒星
But the most massive stars,
其质量至少是太阳三倍
stars that are at least three times our sun’s mass
会坍缩形成无底重力洞 即黑洞
collapse into themselves and create a bottomless well of gravity, a black hole.
而恒星余体中
But from the remnants of stars,
较重的元素再次进入宇宙
heavier elements arecast into the universe
构成星尘 继续孕育新的生命
and it is this star dust that form the seedlings of life itself.
[音乐]
(dramatic music)

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视频概述

恒星的分类以及周期介绍

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收集自网络

翻译译者

窦礼坷

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审核员SX

视频来源

https://www.youtube.com/watch?v=EFO_bsg1sw8

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