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There are all kinds of strange and surprising things in our universe, and astronomers just keep finding more of them.
我们的宇宙中有各种奇怪而又让人惊奇的事物，而天文学家还在不断发现更多这样的事物。
Like planets with huge orbits in triple-star systems, or weird cold jets coming from supermassive black holes.
比如，三星系统中轨道庞大的行星，以及特大质量的黑洞中发射出来的怪异冷射流。
Let's start with the planet.
我们先从行星说起吧。
Last week in Science, a paper was published explaining that scientists have found a triple star system with an exoplanet whose orbit is unlike anything we've seen before.
上周，《科学》期刊上发表了一篇论文。科学家在论文中指出已发现一个带有外星行星的三星系统，而这颗外星行星的轨道不同寻常。
This system is called HD 131399 … but I'll just call it HD for short, or we'll be here all day.
该三星系统名为HD131399，我就简称HD吧，不然名字太长了。
HD is about 320 light-years away from Earth, in the constellation Centaurus.
HD距离地球有近320光年的距离，它位于半人马座之中。
It's around 16 million years old, and its brightest star, HD-A, has almost twice the mass of the Sun.
HD目前已有近1600万年的年龄，而其中最亮的一颗恒星HD-A，其质量是太阳的近2倍。
And researchers from the University of Arizona found an exoplanet that's orbiting this star, called HD-Ab, that's about four times the mass of Jupiter and has a temperature of 580 degrees Celsius.
此外，亚利桑那大学的科学家还发现有一颗外星行星围绕这颗恒星飞行，这颗外星行星名为HD-Ab。该行星的质量是木星的近4倍，温度高达580摄氏度。
This is the very first exoplanet discovered using something called the SPHERE instrument on the Very Large Telescope in Chile.
这是人类通过智利球仪状的甚大望远镜首次发现的外星行星。
It's also one of the coldest and least massive exoplanets to be directly-imaged.
这也是人类首次通过直接成像得到的温度最低、质量最小的外星行星。
Direct imaging is kind of what it sounds like:
所谓直接成像，顾名思义，它
it's similar to photography and it uses either visible or infrared light.
类似于拍照，但用到的却是可见光或红外线。
But it's pretty tough to take a photo of an exoplanet, especially when its light is outshone by three other stars.
但给外星行星拍照是非常困难的，尤其是当拍摄对象的光亮被另外三颗恒星掩盖时更是难上加难。
The SPHERE instrument can help with that, blocking out some of the stars' light and detecting infrared light from young planets.
而甚大望远镜可以降低难度，因为它可以阻隔一些恒星的光亮，并探测到年轻行星发射出的红外光。
Now, what's really weird about HD-Ab is that it's about 82 times as far from its star, as the Earth is from the Sun.
目前，关于HD-Ab十分奇怪的一点是：该行星距离HD-A的距离是地球与太阳距离的近82倍。
Because of this huge orbit, a year on planet HD-Ab would be about 550 Earth-years.
由于其轨道巨大，所以HD-Ab上的一年相当于地球上的近550年。
Which makes it the exoplanet with the widest orbit within a triple system known to scientists.
这就使它成为科学家目前所知的三星系统中轨道最宽的外星行星。
Normally, wide orbits like this aren't very common because the presence of the other two stars makes the orbit unstable.
正常情况下，如此宽的轨道是十分少见的，因为另外两颗恒星的存在会让其轨道不太稳定。
So if HD-Ab's orbit is unstable, it might eventually get ejected from its star system entirely.
所以，一旦轨道不稳定，就可能最终会被三星系统踢出局。
But why does this exoplanet have such a weird orbit in the first place?
不过，首先，我们要问了：这颗外星行星的轨道为何如此怪异呢？
Well, the researchers suggest three main possibilities.
对此，科学家目前猜测了3种可能性。
The first is that it used to be closer to the star, but the gravitational influence from another, unseen planet ejected it out farther.
第一种可能性是：该行星以前跟恒星的距离更近些，但另一颗星体的引力作用导致该行星与其所围绕恒星的距离更远了。不过另一颗星体是我们无法观测到的。
Another explanation is that it used to orbit the other two stars in the system instead, but it got ejected either by those stars or by another planet.
第二种猜测是：这颗行星以前是围绕另外2颗恒星运动的，但它受到了这两颗恒星或者另一颗行星的排斥力作用。
It's also possible that HD-Ab's orbit is weird because … it just is.
第三种猜测是：HD-Ab的轨道之所以奇怪是因为生来如此。
The system might have just kept changing over time until happened to end up the way it is now.
这个三星系统可能一直在变化，直到最后定型的时候，该行星的轨道就是如此。
But whatever the reason, the fact that this exoplanet exists suggests that these multiple-star systems can be a lot more complex than we thought.
无论答案究竟如何，这颗外星行星的存在表明：这个三星系统可能比我们想象得更加复杂。
Another first-of-its-kind discovery published last month in the journal Astronomy &
上个月，《天文学》期刊上还发表了另一个前无古人的猜测。
Astrophysics comes from Chalmers University of Technology in Sweden.
该猜测源自瑞典查尔姆斯理工大学的天体物理学系。
The researchers used the ALMA telescope, also in Chile, to discover a cool, swirling jet coming out of a supermassive black hole.
这些科学家使用了智利的另一个望远镜，即次毫米波阵列望远镜，发现了来自特大质量黑洞的、温度较低的旋转射流。
And this jet is really weird.
这就很奇怪了。
You'll usually find a supermassive black hole at the center of most galaxies, including our own.
在大多数星系中，特大质量黑洞一般会出现在中央，就连在太阳系里也是如此。
Their masses can be millions to billions of times the mass of the Sun -- hence the “supermassive” thing.
特大质量黑洞的质量可达太阳的数百万甚至数十亿倍——所以才有了“特大”的称号。
And they usually have hot jets of fast-moving material coming out of them, which suggests that there's mostly hot gas and dust pouring into them.
此外，特大质量黑洞中通常会有快速移动物质喷发出的高温射流，这就表明总会有高温气体和灰尘涌入其中。
But that is not the case for the supermassive black hole this team found, at the center of the NGC 1377 galaxy.
但该研究组在NGC 1377星系中心发现的情况却截然不同。
This black hole has a cool jet instead, which could mean that it mostly feeds on cool, dense gas and dust.
该黑洞射流的温度较低，这也就意味着涌入其中的基本上是温度较低、密度较高的气体和灰尘。
A supermassive black hole with a jet like this has never been seen in a galaxy before, but their existence might help astronomers figure out how supermassive black holes can grow so quickly.
喷发出这种射流的特大黑洞是闻所未闻的，但这种黑洞的存在或许可以助力天文学家弄清楚特大黑洞数量增长如此之快的原因。
See, the jet coming out of the black hole formed very quickly, in about half a million years.
因为这种黑洞喷发出的射流，其形成速度是非常之快的——基本上50万年就可以形成。
But it already has a mass that's equal to about two million times the mass of the Sun.
但其质量已经是太阳质量的近2亿倍了。
So this black hole is growing at an incredibly fast rate, much faster than regular supermassive black holes -- the ones that have hot jets and feed on hot gas and dust instead.
所以这个黑洞的成长速度是非常惊人的，要比正常的黑洞都要快——正常黑洞是指那些喷发出高温射流，而且会吸食高温气体和灰尘的黑洞。
Which means that its growth might come from the fact that it's accreting, or gathering, cold stuff.
也就是说，这种黑洞之所以成长得如此之快可能是因为它吸收或者说聚集了低温物质。
But! It's also possible that this black hole isn't feeding on cold material at all and its cool jets have nothing to do with the material falling into it.
不过！还有一种可能性：它并未吸收任何低温物质，而且其喷发出的低温射流也与掉落其中的物质毫无关系。
The jet from the supermassive black hole in NGC 1377 is also processing, or swirling around, which jets from other supermassive black holes don't normally do.
此外，NGC 1377中特大质量黑洞中喷发出的射流也在不断的旋转，这也是正常黑洞不会出现的现象。
This might be because the gas and dust is falling into the black hole unevenly.
这可能是因为掉入该黑洞中的气体和灰尘不太均匀。
Or the motion of the jet could be caused by another black hole nearby.
也可能是附近另一个黑洞引起了射流的这种运动。
So we're just now finding out that these cold jets are even a thing.
所以，我们也是不久前才发现竟然存在这种低温射流。
But they are a great way to study how black holes grow.
他们是研究黑洞成长速度惊人的极好素材。
Thank you for watching this episode of SciShow Space News, and thank you especially to our patrons on Patreon who help make this show possible.
感谢收看本期的《太空科学秀》，尤其要感谢我们的忠实粉丝，是你们让节目得以发展。
If you want to help us keep making episodes like this, just go to patreon.com/scishow.
如果大家想助力我们制作类似本期的视频，可以登录patreon.com/scishow。
And don't forget to go to youtube.com/scishowspace and subscribe!
不要忘记订阅youtube.com/scishowspace哦！
