了解宇宙是如何运行的（2010）

How the Universe Works S09E05

Part 8 March 16, 2022, 8:55 a.m.

但奇怪的是，这种情况
But what's weird about this
one is that it happens
每年都会发生
every year.
天文学家很久以前就知道
Astronomers have known for
a long time that there are these
有这些新星的存在
cases of these nova that go off,
你知道，有些规律，每10年
you know, somewhat regularly,
every 10 years,
或每100年
every 100 years.
但每年都能发现一次爆♥炸♥的
But finding one that goes off
是一个了不起的发现
every year is
a remarkable discovery.
就像超新星一样
Much like supernovas,
新星发生在一个接近的双星系统中
novas occur in a close
binary system,
其中一颗白矮星和另一颗恒星♥相♥互围绕着对方运行
where a white dwarf and
another star orbit each other.
白矮星从伴星中
The white dwarf pulls in
hydrogen
吸收氢
from the companion star.
气体落到它的表面
The gas falls onto its surface.
所以当氢堆积起来，
And so as
that hydrogen piles up,
最终，它达到了氢可以熔合成氦
eventually, it gets to
the point where
并爆♥炸♥的程度，于是就爆♥炸♥了
it can fuse into helium
and goes bang.
但超新星中
In supernovas,
核聚变在恒星的核心深处发生
fusion happens deep inside
the star's core,
但在新星中，核聚变只发生在表面
but in novas, fusion only
occurs on the surface.
一场爆♥炸♥划过白矮星的表面
An explosion flares across
the white dwarf's exterior,
将未燃尽的氢抛向太空
hurling unburned hydrogen
out into space.
结果……一个叫做残骸的天体
The result... an object
called a remnant.
新星 M31N 的残骸有400光年宽
The remnant from Nova M31N
is 400 light-years wide.
这个特殊的残骸甚至
This particular remnant is much
比超新星残骸还要大
bigger than even
supernova remnants.
它比大多数正常的残骸
It's much larger, much denser
更大、更密、更亮
and brighter than most
normal remnants are.
如果恒星
But that makes sense
如此频繁地发光，这就说得通了
if the star flares up so often.
想想那颗闪耀了数百万年的恒星
Think about the star flaring
away for millions of years.
你建造了一个巨大的新星遗迹
You build up a gigantic
nova remnant.
重复的耀斑解释了
The repeating flares explain
残骸的巨大尺寸
the huge size of the remnant.
但为什么新星会如此频繁地爆♥炸♥呢？
But why does the nova explode
so frequently?
传统观点，我们认为当一颗新星
Classically, we thought that
when a nova went off
在白矮星表面
on the surface of
爆♥炸♥时，白矮星的质量
a white dwarf star that
the white dwarf star's mass
不会有太大的变化
didn't change very much.
或者它变小了
Or maybe it got
a little smaller.
现在我们认为在新星形成后
Now we think that after a nova,
白矮星的质量增加了一些
the white dwarf
gains a bit of mass.
像 M31N 这样反复出现的新星，从伴星上偷走的质量
Recurrent novas, like
M31N, steal more mass from
比它们在每次爆♥炸♥中释放出来的质量还要多
their companion star than they
blow off in each explosion.
一些恒星的质量越来越大
Some gain more and more mass,
爆♥炸♥频率越来越高
exploding more frequently
until they reach
直到它们达到钱德拉塞卡极限
the Chandrasekhar limit
成为一颗全面爆发的超新星
and go full-on supernova.
M31N 很可能
M31N may very well be
是向我们展示一些新星系统
the missing link that shows us
最终会变成超新星系统的
that some nova systems
eventually become
缺失环节
supernova systems.
弄清新星是如何变成超新星的
Working out how novas become
以及为什么一些超新星会失败
supernovas and why some
supernovas fail
可能会帮助我们理解白矮星爆♥炸♥的原因
might help us understand what
makes white dwarfs explode.
但就在我们以为有机会了的时候
But just when we think
we get a break,
白矮星又给我们带来了另一颗重磅信息……
white dwarfs hit us
with another bombshell...
死亡射线
death rays.
白矮星可以在猛烈的超新星中爆♥炸♥
White dwarfs can explode
in violent supernovas,
但这不是它们唯一的致命伎俩
but that's not
their only deadly trick.
他们还可能创造出宇宙中
They might also create the most
最具磁性和最可怕的野兽……
magnetic and terrifying beast
in the universe...
磁星
A magnetar.
磁星是可怕的它们是
Magnetars are scary.
They just are.
我是说，从名字里就可知
I mean, it's even in the name.
磁星这个词听起来很可怕
The word magnetar sounds scary.
它们是宇宙中
They're the reigning champion of
最大磁场的卫冕冠军
the largest magnetic field in
the universe.
萨特:磁星周围的磁场非常强
SUTTER: The magnetic fields
around magnetars are so strong
可以拉伸和扭曲单个原子
that they can stretch
and distort individual atoms.
他们能把原子变成又长又细的铅笔形状
They can turn an atom into
a long, thin pencil shape.
一旦开始把原子拉伸成这种形状
Once you start stretching
atoms out into this shape,
它们就不能再以通常的方式结合在一起了
they can't bond together
in the usual ways anymore.
所以你可以扔掉
And so you can just throw out
世界上所有的化学教科书
<意思是此时的原子已经不能进行任何的化学反应了>
every chemistry textbook
in the world.
布洛克:如果一个宇航员不幸地
BULLOCK: If an astronaut were
unlucky enough to get close to
靠近了一颗磁星，比方说
a magnetar, say, within
在六七百英里之内，这个宇航员
600, 700 miles,
the whole body of the astronaut
整个身体都会被完全毁灭
would be completely obliterated.
它们或多或少会溶解
They would more
or less dissolve.
这些可怕怪物的起源是个谜
The origin of these
fearsome creatures is a mystery,
但一定是某种非常猛烈的东西
but it must be something
very violent.
我们认为它们在形成时会发生某个迹象
We think they send out
a clue as they form,
即穿过宇宙的强大的能量爆♥炸♥
powerful blasts of energy
shooting across the cosmos.
在过去的几十年里，我们注意到这些非常奇怪
In the past few decades,
we've noticed these very odd,
非常混乱，非常短暂的
very confusing and very brief
强烈的电波能量的闪光
flashes of intense radio energy.
它们被称为快速电波爆发，简称 FRBs
They're known as fast
radio bursts, or FRBs.
有些快速电波爆发不会重复爆发一次就结束
Some FRBs don't repeat.
They're one and done.
所以这里所说的是在不到一秒的时间里
So you're talking about
an incredible amount
释放出难以置信的能量
of energy released in less
than a second,
然后就结束了
then it's over.
因为这些不重复的快速电波爆发
Because these
non-repeating FRBs are
非常强大，我们认为它们可能来自一次巨大的碰撞
so powerful, we think they could
come from a huge collision.
碰撞的物体越重、密度越大
The heavier and denser
the objects colliding,
爆♥炸♥就越大
the bigger the bang.
新的研究表明，一颗白矮星撞击一颗
New research suggests a white
dwarf star hitting a dense,
高密度大质量的中子星可能足以产生
heavy neutron star could be
enough to birth
一颗磁星
a magnetar,