Three Earth-like planets discovered orbiting dwarf star

科学家在矮星轨道上发现3颗类地行星

Story highlights（内容梗概）

    Researchers have discovered three potentially habitable, Earth-like worlds orbiting a dwarf star

    The star and its planets are 40 light-years away in another star system

    研究者发现3颗潜在宜居的类地行星环绕着一颗矮星旋转运行。

    这颗矮星和它的行星距离另一个星系有40光年。

The ultracool dwarf star, known as TRAPPIST-1, isn't the kind of star scientists expected to be a hub for planets. It's at the end of the range for what classifies as a star: half the temperature and a tenth the mass of the sun. TRAPPIST-1 is red, barely larger than Jupiter and too dim to be seen with the naked eye or even amateur telescopes from Earth.

在矮星区域范围内有一颗超冷恒星，被称为 TRAPPIST-1，它不像科学家们预期的那样是行星的中心。它处在被分类为行星的边缘：温度是太阳的一半，体积是太阳的十分之一。TRAPPIST-1是红色的，勉强比木星大一些，但是星体光线太弱导致在地球上用裸眼甚至天文望远镜都难以看到。

But these tiny stars, along with brown dwarfs, are long-lived, common in the Milky Way and represent 25-50% of stellar objects in the galaxy, said study researcher Julien de Wit, a postdoctoral associate with MIT's Department of Earth, Atmospheric and Planetary Sciences.

但是这些围绕着矮星的小行星已经存在了很久了，通常在银河系中有着25-50%这样的星体，一位麻省理工学院地球科学系、大气层及行星科学系的研究者Julien de Wit说道。

They were largely overlooked until researcher Michaël Gillon of the University of Liège in Belgium decided to take a risk and study the space around one of these dwarves. It paid off.

它们几乎被忽略直到位于比利时烈日大学的一名研究者Michaël Gillon决定冒险研究这些矮星周围区域才发现的，它起作用了。

Over the course of 62 nights from September to December 2015, researchers led by Gillon used a telescope, also called TRAPPIST (transiting planets and planetesimals small telescope), to observe its starlight and changes in brightness. The team saw shadows, like little eclipses, periodically interrupting the steady pattern of starlight. Using a telescope that can detect infrared light added an advantage that visible light camera programs don't provide.

从9月到12月超过62个夜晚的历程，由Gillon带头的研究者们使用一种天文望远镜，也叫TRAPPIST（凌日行星和星子级望远镜），为了观察星体光线和亮度的变化。这个团队看过像小型日食那样的阴影，周期性的影响处于稳定模式的星光。使用能探测到红外线的天文望远镜比只能拍摄到可见光的相机多了个优势。

The planets are about the size of Earth and given the proximity of two of them to the dwarf star, they receive about four times the amount of radiation than we do from the sun, which suggests they are in the "habitable zone." According to Burgasser, the "habitable zone," determines how close a planet is to the star that it orbits and given the temperature of the planet based on that proximity, it could have water on the surface. This core ingredient for life as we know it also suggests there could be an atmosphere and habitable regions on the planets themselves.

这3个行星和地球和地球的大小差不多，其中有两个与矮行星邻近，他们接收到大约4倍于太阳放射的辐射量，这是一个“宜居带”。根据布尔加瑟星，这个“宜居带”决定了行星和邻近行星的轨道距离以及温度，可能在行星表名有水的存在。我们都知道这是生命的核心组成部分。它也暗示着在行星间可能存在有大气层和可居住区域。

Less is known about the third outer planet, which receives twice the amount of radiation that Earth does, but it is potentially in the habitable zone as well.

很少有人知道第三带外行星，它接收了两倍数量于地球的辐射，但是它也是在潜在宜居带内。

Like the moon, the researchers believe the two planets closest to the star are tidally locked. This means that the planets always face one way to the star. One side of the planet is perpetually night, while the other is always day.

比如月亮，研究者相信离月亮最近的两个行星已经被潮汐力锁定了。这意味着行星总是有一面是朝着星体的。其中有一面永远是夜晚，另外一面永远是白天。

These results are just the beginning of a study that will continue for years. The researchers are already working on observations to see if the planets have water or methane molecules.

这些研究结果才刚刚开始并将会延续很多年。研究者们已经做好观察这些行星是否存在水或甲烷分子的准备。

The planets are the perfect target to be studied at 40 light-years away, but that doesn't mean we will reach them anytime soon. With current technology, it would take millions of years for an expedition to reach these planets. But from a research perspective, they provide a close opportunity and the best target to search for life beyond Earth and our solar system. What we find also could change how we determine the creation of life as we know it.

这些行星是研究40光年内行星最完美的目标，但是这不意味着我们可以在近期到达这些行星。以目前的科技，探索这些行星将会耗费数百万年的时间。但是从研究视角出发，他们提供了一个探索地球以外和太阳系内生命的最佳途径和目标。我们所探索的一切也可能改变我们现在所认知的对生命起源的定义。

The telescopes these researchers use to study the planets are even more precise than Hubble. In 2018, they can begin using the James Webb Space Telescope, which will allow the scientists to observe the shell of an atmosphere if it exists for these planets, and even what chemicals comprise that atmosphere. It will also provide more detailed information about the planets' composition, temperature and pressure, according to de Wit.

这些研究者用来研究这些行星的天文望远镜设置比哈勃望远镜精确。到了2018，他们将开始使用詹姆斯·韦伯空间望远镜，它将能让科学家们观察大气层的外层是否因为这些行星存在的，甚至能知道大气层是由哪些化学物质组成的。它还能获取更多关于行星的构成的信息，据de Wit所说。     

The next generation of telescopes will also be able to search for the subtle signatures of biomarkers, like oxygen, de Wit said.

de Wit提到，下一代天文望远镜还将支持探索生物指标的细微特征，如氧气。

Burgasser is excited about what this discovery means for the future, which he anticipates will include more interest in these tiny stars and what they can support.

Burgasser对这次具有象征意义的发现感到兴奋，他预期将来会投入更多的兴趣到这些小行星且提供他们所能提供的。

Burgasser, who has made the study of dwarf stars his life's work, says that TRAPPIST-1 was initially studied quite a bit, but the planets around it have not been revealed until now.

Burgasser一生都在研究矮行星，他说TRAPPIST-1是最初的时候研究地比较多，但是直到现在都没有在它周围有行星存在。

"It's like you've known this good friend your whole life and suddenly find out that they're royalty," he said.

他说：“这就好像是你已经知道有些人你把他们当做一生的好友，但突然你又发现他们其实是皇室。”

Forward from : http://edition.cnn.com/2016/05/02/health/three-habitable-planets-earth-dwarf-star/index.html

来源：时间去哪儿了博客（微信/QQ号：903918446），转载请保留出处和链接！

本文链接：http://timegowhere.com/post/Translate20160503.html