美國(guó)國(guó)家航空航天局發(fā)現(xiàn)了一個(gè)六星系統(tǒng)

美國(guó)國(guó)家航空航天局發(fā)現(xiàn)了一個(gè)六星系統(tǒng)，在這個(gè)系統(tǒng)中，恒星之間不斷地互相遮擋

Stars can get in pretty peculiar configurations, which are often difficult to spot and even more difficult to model. But system TIC 168789840 truly is almost too extraordinary to be described. It is the first six-star system discovered where each pair of stars are eclipsing binaries.

恒星可以形成非常奇特的形狀，通常很難發(fā)現(xiàn)，甚至更難建立模型。但TIC 168789840系統(tǒng)實(shí)在是太不尋常了，難以描述。這是第一個(gè)發(fā)現(xiàn)每一對(duì)恒星都是日食雙星的六恒星系統(tǒng)。

Each star in the three pairings – A, B, and C – orbit each other in a matter of days. So, from the point of view of our planet, some of the stars in the system get covered partially by their companion. If this was not already exciting, the A and C systems orbit each other every four years. And those two systems orbit the B system every 2,000 years. A truly incredible stellar dance.

這三對(duì)恒星——A、B和C——在數(shù)天內(nèi)圍繞彼此運(yùn)行。所以，從我們行星的角度來(lái)看，這個(gè)系統(tǒng)中的一些恒星被它們的伴星部分覆蓋。如果這還不令人興奮的話，A和C系統(tǒng)每四年繞對(duì)方軌道運(yùn)行一次。這兩個(gè)系統(tǒng)每2000年繞B系統(tǒng)轉(zhuǎn)一圈。是一個(gè)真正令人難以置信的恒星舞蹈。

The study is accepted for publication in The Astronomical Journal. The team describes how this system is similar to Castor, the second brightest object in the Gemini constellation. Castor is also a six-star system, but only one pair in the Castor system eclipses from our point of view.

這項(xiàng)研究被接受發(fā)表在《天文學(xué)雜志》上。該團(tuán)隊(duì)描述了這個(gè)系統(tǒng)與雙子星座中第二亮的星座——蓖麻星是如何相似的。Castor也是一個(gè)六星系統(tǒng)，但從我們的觀點(diǎn)來(lái)看，在Castor系統(tǒng)中只有一對(duì)月食。

Dr Alfredo Carpineti

Another difference is just how similar the pairs in TIC 168789840 (also known by the equally catchy TYC 7037-89-1) are. They could be truly seen as triplets. And researchers believe that this is a crucial clue for how the system might have formed and evolved.

另一個(gè)區(qū)別是TIC 168789840(也被同樣引人注目的TYC 7037-89-1所知)中的對(duì)有多相似。他們可以被視為三胞胎。研究人員認(rèn)為，這是研究該系統(tǒng)如何形成和進(jìn)化的關(guān)鍵線索。

“In this work, we have presented the discovery of the first known sextuply-eclipsing sextuple star system TIC 168789840,” the international team wrote in the paper, which is available on the ArXiv.

“在這項(xiàng)工作中，我們展示了第一個(gè)已知的六次日食六星系TIC 168789840的發(fā)現(xiàn)，”國(guó)際團(tuán)隊(duì)在論文中寫(xiě)道，該論文可以在ArXiv上找到。

“TIC 168789840 is a fascinating system that naturally merits additional observation and analysis. Though quite similar to the famous Castor system, the “triplet” nature of TIC 168789840 combined with the presence of three primary and three secondary eclipses enable further investigations into its stellar formation and evolution.”

TIC 168789840是一個(gè)迷人的系統(tǒng)，自然值得額外的觀察和分析。雖然與著名的星輪星系非常相似，但TIC 168789840的“三重”性質(zhì)，加上三次主食和三次次食的存在，使我們能夠進(jìn)一步研究其恒星的形成和演化。

This schematic shows the configuration of the sextuple star system TIC 168789840. Image Credit: NASA's Goddard Space Flight Center

The team put forward the possibility that star A and C form as a binary with a thick disk of material around them. They eventually encountered star B, which is captured on a wider orbit. All this excitement caused the collapse of gas in the disk into smaller companions, orbiting on roughly the same plane. It is a compelling hypothesis, but without more data, it remains highly speculative.

該研究小組提出了恒星A和C以雙星形式存在的可能性，它們周?chē)幸粚雍窈竦奈镔|(zhì)圓盤(pán)。他們最終遇到了B星，它被捕獲在一個(gè)更寬的軌道上。所有這些刺激導(dǎo)致了圓盤(pán)內(nèi)氣體的坍縮，變成更小的伴星，在大致相同的平面上繞軌道運(yùn)行。這是一個(gè)令人信服的假設(shè)，但沒(méi)有更多的數(shù)據(jù)，它仍然是高度推測(cè)的。

The discovery of this system is thanks to NASA’s Transiting Exoplanet Survey Satellite (TESS). TESS is keeping an eye on millions of stars and studying about 200,000 in detail. The team was able to use a machine-learning algorithm to find eclipsing binaries among 80 million stars. Among these, at least 100 were identified to be in systems with more than three stars.

這個(gè)系統(tǒng)的發(fā)現(xiàn)要感謝美國(guó)宇航局的凌日系外行星勘測(cè)衛(wèi)星(TESS)。TESS正密切關(guān)注著數(shù)百萬(wàn)顆恒星，并詳細(xì)研究了大約20萬(wàn)顆恒星。該團(tuán)隊(duì)能夠使用機(jī)器學(xué)習(xí)算法在8000萬(wàn)顆恒星中找到日食雙星。在這些星系中，至少有100個(gè)被確認(rèn)屬于擁有3顆以上恒星的星系。

TIC 168789840 is located 1,900 light-years away in the constellation Eridanus, a southern sky constellation named after the Latin name of Italy’s longest river.

TIC 168789840位于1900光年之外的波江星座，這是一個(gè)南方的天空星座，以意大利最長(zhǎng)河流的拉丁名字命名。