像《星球大戰(zhàn)》中發(fā)現(xiàn)的火山行星一樣熾熱的——外星球

Although thousands of exoplanets have been discovered outside our solar system since the 1990s, astronomers are still hunting for something that remains elusive there: exomoons.

盡管自20世紀90年代以來，在太陽系外已經(jīng)發(fā)現(xiàn)了數(shù)千顆系外行星，但天文學家仍在尋找一些在那里仍然難以捉摸的東西：系外衛(wèi)星。

Over the last year, a few researchers have suggested potential evidence for locating these small moons around exoplanets, but nothing has been confirmed.

在過去的一年里，一些研究人員提出了在系外行星周圍定位這些小衛(wèi)星的潛在證據(jù)，但沒有任何證據(jù)得到證實。

Now, researchers believe they have found possible indications of an exomoon orbiting a giant, scorching exoplanet in the Lepus constellation, 550 light-years from Earth.

如今，研究人員相信他們已經(jīng)發(fā)現(xiàn)了可能的跡象，表明在距離地球550光年的Lepus星座中，有一顆外星系圍繞著一顆巨大的、灼熱的系外行星運行。
And it's comparable to Mustafar, a small volcanic planet sandwiched between two gas giants where Anakin Skywalker undergoes his dark, painful transition into Darth Vader in "Star Wars: Episode III -- Revenge of the Sith."

這和穆斯塔法很像。穆斯塔法是一顆火山星球，夾在兩顆氣態(tài)巨星之間，阿納金·天行者在《星球大戰(zhàn)：第三集——西斯的復仇》中經(jīng)歷了向達斯·維德的黑暗、痛苦的轉變。

It would be a dangerous volcanic world with a molten surface of lava, a place where Jedis go to die, perilously familiar to Anakin Skywalker," said Apurva Oza, study author and postdoctoral fellow at the Physics Institute of the University of Bern.

伯爾尼大學物理研究所的研究作者和博士后阿普爾瓦·奧扎說：“這將是一個危險的火山世界，有著熔巖的熔融表面，絕地武士會為此死去，這對阿納金·天行者來說是非常熟悉的。”

The WASP 49-b exoplanet system includes a gas giant that completes one orbit around its star every three days. The planet was discovered orbiting the WASP 49 star in 2012 via the transit method, which is when an exoplanet passes in front of its star, causing detectable dips in starlight.

WASP 49-b系外行星系統(tǒng)包括一顆氣體巨星，每三天繞其恒星運行一周。2012年，人們通過凌日法發(fā)現(xiàn)了這顆圍繞WASP 49恒星運行的行星。凌日法是指一顆系外行星從其恒星前方經(jīng)過，導致恒星光線出現(xiàn)可探測到的傾角。

Astronomers believe they found evidence for a moon due to the presence of sodium gas where they didn't expect to find it. The researchers published their findings this week in The Astrophysical Journal.

天文學家認為，他們發(fā)現(xiàn)了月球的證據(jù)，是因為在他們沒想到會發(fā)現(xiàn)它的地方存在鈉氣體。研究人員本周在《天體物理學雜志》上發(fā)表了他們的發(fā)現(xiàn)。

To understand why sodium gas is a key indicator, the astronomers looked at Jupiter's volcanic moon Io - the most volcanically active body in our solar system, according to NASA.

為了理解為什么鈉氣體是一個關鍵指標，天文學家觀察了木星的火山衛(wèi)星IO——根據(jù)美國宇航局的說法，它是太陽系中火山活動最活躍的天體。

Volcanoes on Io belch out sodium gas, which is then pulled around Jupiter in a cloud, according to previous research.

根據(jù)先前的研究，IO上的火山噴發(fā)出鈉氣體，然后這些鈉氣體被云層環(huán)繞在木星周圍。
When applying the Jupiter and Io model to the Wasp 49-b system, "the sodium is right where it should be," Oza said.

奧扎說，當將木星和IO模型應用于黃蜂49-B星系時，“鈉就在它應該在的地方。”

But their discovery implies that the exomoon is actually losing mass through the emission of sodium gas at high altitude.

但他們的發(fā)現(xiàn)意味著，外月球實際上是通過在高空釋放鈉氣體而失去質量的。

"Sodium and potassium lines are quantum treasures to us astronomers because they are extremely bright," Oza said.

奧扎說：“鈉和鉀線對我們天文學家來說是量子寶藏，因為它們非常明亮。”

"The vintage street lamps that light up our streets with yellow haze is akin to the gas we are now detecting in the spectra of a dozen exoplanets.

“用黃色煙霧照亮街道的老式路燈，類似于我們現(xiàn)在在十幾顆系外行星光譜中探測到的氣體。”

"And a system including a star closely orbited by a giant planet with its own moon can actually exist stably for billions of years.

“包括一顆恒星在內的星系，由一顆擁有自己衛(wèi)星的巨型行星緊密環(huán)繞，實際上可以穩(wěn)定存在數(shù)十億年。”

"The enormous tidal forces in such a system are the key to everything," Oza said.

“在這樣一個星系中，巨大的潮汐力是一切的關鍵。”奧扎說。

Tides create stability for the moon's orbit, which also help to heat it and keep it volcanically active.The researchers also found other potential star systems where moons could be hiding from our view, but they need to find more clues.

潮汐為月球軌道創(chuàng)造了穩(wěn)定性，這也有助于加熱月球并使其保持火山活動。研究人員還發(fā)現(xiàn)了其他可能的恒星星系，那里的衛(wèi)星可能隱藏在我們的視線之外，但這一切都還需要更多的線索才能了解。