科學家發現擁有三顆太陽的行星

“Star Wars” fans love Tatooine and its twin suns, but astronomers working with one of the world’s biggest telescopes have done Luke Skywalker’s home planet one better.

《星球大戰》中的塔圖因星球（Tatooine，天行者家族的故鄉行星）以及它所繞行的雙子太陽深受粉絲的喜愛，然而日前天文學家們利用世界上最大的天文望遠鏡之一發現了一個比盧克·天行者的故鄉所在的星球更勝一籌的行星。

They’ve discovered a bizarre world with not two but three suns ― and seasons that last longer than a human lifetime.

他們發現了一個奇妙的新世界，在這裏，你能看到不止兩個太陽，而是三個，同時，每一個季節都比人類的一生還要漫長。

Known as HD 131399Ab, the unusual exoplanet is located 320 light-years from Earth in the large southern constellation Centaurus. It’s a gas giant like Jupiter but about four times as massive.

這顆不同尋常的地外行星被命名爲HD 131399Ab, 它位於南方巨大的人馬星座上，距地球320光年。它是類似於木星的氣體巨星，但它的體積是木星的四倍。

And while it’s one of the coldest exoplanets ever to be directly imaged by a telescope (rather than detected as a result of the dimming of starlight as it passes in front of its host star), HD 131399Ab is very hot by human standards. The average temperature exceeds 1,000 degrees Fahrenheit.

雖然它是溫度最冷的地外行星中被天文望遠鏡直接捕捉到影像的一個（而不是在從其宿星前經過時被檢測到一抹暗淡的星光），HD 131399Ab星球上的平均溫度超過華氏1000度，遠超人類耐熱標準。

In short, HD 131399Ab isn’t the kind of place you’d like to call home. (And there’s no hint that it harbors alien life.) But if you could live there, you’d find its sky a most peculiar place: You’d see either constant daylight or triple sunsets, depending on the season.

簡而言之，HD 131399Ab行星絕不是一個宜居的地方（並且這裏也沒有發現外星生命跡象）。但是如果你有機會住在那兒，你會看到最光怪陸離的天空：根據季節的不同，你可能看到永晝，也有可能同時欣賞三個落日。

And each season on HD 131399Ab lasts about 300 years.

HD 131399Ab行星的每一個季節都持續三百年左右。

HD 131399Ab orbits the system’s brightest star, HD 131399A, at a distance of about 7.6 billion miles. That’s roughly 82 times the average distance from the Earth to the sun ― and, according to the astronomers behind the discovery, the widest orbit ever seen for a planet in a triple-star system.

HD 131399Ab繞行的星球是其星系中最亮的一顆——HD 131399A行星，兩者之間的距離大概是76億英里。這一距離大約是地日平均距離的82倍，並且，發現該行星的天文學家稱，HD 131399Ab星球的繞行軌道在三星星系中是最寬的。

The other two stars in the system, HD 131399B and HD 131399C, twirl around each other as they orbit HD 131399A at a distance that’s 300 to 400 times greater than the distance from the Earth to the sun.

這一星系中另外兩顆行星，HD 131399B行星 和 HD 131399C行星在繞行HD 131399A行星的同時互繞旋轉，它們繞行的距離則是地日距離的300至400倍。

The newfound planet was discovered using the European Southern Observatory’s Very Large Telescope in northern Chile. The ESO is supported by Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland Chile and the United Kingdom. Researchers published a paper on their findings Thursday in the journal Science.

發現HD 131399Ab行星的天文望遠鏡是位於智利北部的歐南臺巨大望遠鏡陣列。歐南臺是由澳大利亞、比利時、巴西、捷克共和國、丹麥、法國、芬蘭、德國、意大利、荷蘭、波蘭、葡萄牙、西班牙、瑞典、瑞士、智利和英國這些國家聯合創辦的。研究人員週四在《科學》雜誌上發表文章闡述他們的新發現。

Kevin Wagner, a University of Arizona Ph.D. student and the paper’s lead author, told The Huffington Post in an email that the system’s configuration is “surprising and extreme.”

凱文·瓦格納是亞利桑那州一所大學的博士研究生，他是這篇文章的第一作者，他在電郵中告訴《赫芬頓郵報》的記者，新行星所在的星系結構令人歎爲觀止。

It’s also a bit precarious.

但這顆行星同時也潛伏着危機。

“If the planet was further away from the most massive star in the system, it would be kicked out of the system,” Dr. Daniel Apai, assistant professor of astronomy and planetary sciences at the university and co-author of the paper, said in a news release.

丹尼爾·阿派博士是這所大學天文與行星專業的助理教授，同時也是這篇文章的聯合作者，他在報道中稱：“如果HD 131399Ab行星離星系中最大的行星再遠一點的話，它就會被踢出這一星系。”

“Our computer simulations have shown that this type of orbit can be stable, but if you change things around just a little bit, it can become unstable very quickly.”

“我們做出的電腦模擬效果圖顯示，這一星系的運行軌道一般來說是穩定的，但是一旦其周圍的物體發生變動，它就會瞬間變得不穩定。”

Stable or not, HD 131399A is fascinating to astronomers in part because it helps fill in gaps in our knowledge of how planets form and change orbit.

無論穩定與否，HD 131399A星系對天文學家們有着巨大的吸引力，一部分是因爲它的發現填補了我們現有知識的一處空白，即行星如何形成以及如何變動軌道。