天文學家首次發現太陽系外也有'月球'的證據

Astronomers have announced the possible discovery of the first known moon outside our Solar System.

天文學家日前宣佈，他們可能在我們的太陽系外發現了第一顆已知的月球。

This "exomoon" is not like any in our cosmic neighbourhood: it's the size of Neptune and orbits a planet the size of Jupiter -- but with 10 times the mass.

這顆“系外月球”與我們宇宙裏的任何東西都不同：它的體型有海王星那麼大，繞着一顆木星大小的行星旋轉--但這顆行星的質量是木星的10倍。

The object was spotted in data from Nasa's Kepler spacecraft, and later observed using the Hubble telescope.

在該星體納入美國宇航局開普勒探測器的數據後，天文學家使用哈勃望遠鏡進行了觀測。

Astronomers David Kipping and Alex Teachey have published their results in Science Advances journal.

天文學家戴維·基平和阿萊克斯·提徹已將他們的成果發表在《科學進展》雜誌上。

But they say that further observations are needed to understand the distant planetary system.

但是他們表示，需要進一步的觀察才能理解這個遙遠的行星系。

"We've tried our best to rule out other possibilities such as spacecraft anomalies, other planets in the system or stellar activity, but we're unable to find any other single hypothesis which can explain all of the data we have," said Dr Kipping, from Columbia University in New York.

來自紐約哥倫比亞大學的基平博士稱：“對所觀測到的現象，我們已盡力排除其他可能性，如探測器異常、太陽系中的其他行星或恆星活動，但我們無法找到任何其他單一假設來解釋我們的數據。”

To date, astronomers have discovered more than 3,500 exoplanets -- worlds orbiting stars other than the Sun.

迄今爲止，天文學家已發現超過3500顆系外行星--即環繞除太陽以外運行的星體。

A hunt for exomoons -- bodies that orbit these distant planets -- has proceeded in parallel. But so far, these natural satellites have lingered at the limits of detection with current techniques.

天文學家也在同時尋找“系外月球”--即圍繞遙遠行星的星體。但到目前爲止，這些天然星體很難被現有技術的探測到。

The researchers monitored a planet known as Kepler 1625b as it passed in front of its parent star.

研究人員是在這顆被命名爲開普勒1625b的星體環繞其母星運行的時候，對其進行的監測。