科學(xué)家們剛剛在銀河系發(fā)現(xiàn)了一個“不可能的”黑洞

Scientists Just Found an "Impossible" Black Hole in The Milky Way Galaxy

科學(xué)家們剛剛在銀河系發(fā)現(xiàn)了一個“不可能的”黑洞

A new black hole search method has just yielded fruit, and boy is it juicy. Astronomers have found a stellar-mass black hole clocking in at around 70 times the mass of the Sun - but according to current models of stellar evolution, its size is impossible, at least in the Milky Way.

一種新的黑洞搜索方法剛剛產(chǎn)生了成果，真是太棒了。天文學(xué)家發(fā)現(xiàn)了一個恒星質(zhì)量的黑洞，其質(zhì)量大約是太陽質(zhì)量的70倍，但根據(jù)目前的恒星演化模型，它的大小是不可能的，至少在銀河系是這樣。

The chemical composition of our galaxy's most massive stars suggests that they lose most of their mass at the end of their lives through explosions and powerful stellar winds, before the star's core collapses into a black hole.

我們銀河系中質(zhì)量最大的恒星的化學(xué)成分表明，它們在生命的最后階段通過爆炸和強(qiáng)大的恒星風(fēng)失去了大部分質(zhì)量，這時恒星的核心還沒有坍縮成黑洞。

The hefty stars in the mass range that could produce a black hole are expected to end their lives in what is called a pair-instability supernova that completely obliterates the stellar core. So astronomers are scratching their heads trying to figure out how the black hole - named LB-1 - got so chonky.

在質(zhì)量范圍內(nèi)可以產(chǎn)生黑洞的巨大恒星預(yù)計(jì)將在所謂的對不穩(wěn)定超新星中結(jié)束生命，該超新星將徹底摧毀恒星核心。因此，天文學(xué)家們絞盡腦汁，試圖弄清楚這個名為LB-1的黑洞是如何變得如此“軟硬”的。

Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution, said astronomer Jifeng Liu of the National Astronomical Observatory of China.

中國國家天文臺的天文學(xué)家劉繼峰說:“根據(jù)目前大多數(shù)恒星演化模型，這種質(zhì)量的黑洞甚至不應(yīng)該存在于我們的星系中。”

LB-1 is twice as massive as what we thought possible. Now theorists will have to take up the challenge of explaining its formation.

“LB-1的質(zhì)量是我們認(rèn)為可能的兩倍。現(xiàn)在，理論家們將不得不接受解釋其形成的挑戰(zhàn)。”

The method by which the black hole was detected was really clever.

探測黑洞的方法確實(shí)很聰明。

Black holes, unless they are actively accreting matter, a process that glows in several wavelengths across the spectrum, are literally invisible. They don't give off any radiation we can detect - no light, no radio waves, no X-rays, zip, zilch. But that doesn't mean we have nothing in our detection toolkit.

黑洞，除非它們在積極地吸收物質(zhì)，這個過程會在光譜中發(fā)出幾個波長的光，否則是看不見的。它們不會發(fā)出我們能探測到的任何輻射——沒有光，沒有無線電波，沒有x射線，什么都沒有。但這并不意味著我們的檢測工具箱里什么都沒有。

Way back in 1783, English natural scientist John Michell (the first person to propose the existence of black holes) suggested that black holes may be detectable if they were orbited by something that does emit light - such as a companion star - which would be tugged around the resulting binary system's mutual centre of gravity.

早在1783年,英語自然科學(xué)家約翰·米歇爾(第一個提出黑洞)的存在表明,黑洞可能檢測到如果他們被東西環(huán)繞發(fā)光——比如伴星——這將是拖著周圍產(chǎn)生的二進(jìn)制系統(tǒng)的共同的重心。

This is now known as the radial velocity method, and it's one of the main ways we search for and confirm the existence of hard-to-see exoplanets as they exert a small gravitational influence on their stars. And it can also be used to find other invisible things - such as black holes.

這就是現(xiàn)在所知的徑向速度法，它是我們尋找和確認(rèn)難以觀測的系外行星存在的主要方法之一，因?yàn)樗鼈儗ζ浜阈怯泻苄〉囊τ绊?。它還可以用來發(fā)現(xiàn)其他不可見的東西——比如黑洞。

Liu and his colleagues were using the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in China to search for these wobbly stars, and got a hit on a main-sequence blue giant star.

劉和他的同事使用中國的大天空區(qū)域多目標(biāo)光纖光譜望遠(yuǎn)鏡(LAMOST)來尋找這些搖擺不定的恒星，并發(fā)現(xiàn)了一顆主序藍(lán)巨星。

But it took follow-up observations using the powerful Gran Telescopio Canarias in Spain and the Keck Observatory in the US to reveal the amazing nature of what the scientists had found.

但科學(xué)家們利用西班牙強(qiáng)大的Gran Telescopio Canarias和美國的Keck天文臺進(jìn)行了后續(xù)觀測，揭示了科學(xué)家們所發(fā)現(xiàn)的驚人性質(zhì)。

The star, around 35 million years old and clocking in at around eight times the mass of the Sun, is orbiting the black hole every 79 days on what the researchers called a "surprisingly circular" orbit.

這顆恒星大約有3500萬年的歷史，質(zhì)量大約是太陽的8倍。它每79天繞黑洞運(yùn)行一次，研究人員稱之為“令人驚訝的圓形”軌道。

There has been another black hole of a similar mass range detected, clocking in at around 62 solar masses - it was created as a result of a collision between two black holes in a binary pair - GW150914, the first direct detection of gravitational waves ever made by humans. It's not in the Milky Way, but it does offer one way such a black hole can form.

還有一個類似質(zhì)量范圍的黑洞被探測到，大約有62個太陽質(zhì)量——它是由兩個黑洞以雙子星對碰撞產(chǎn)生的——GW150914，這是人類首次直接探測到引力波。它不在銀河系中，但它確實(shí)提供了一種黑洞形成的方式。

The research has been published in Nature.

這項(xiàng)研究發(fā)表在《自然》雜志上。