气体行星独特的运动轨迹使其形成了彗星尾巴(有

A planet called HD 209458b, aka Osiris, orbits its star so closely that it is losing some of its atmosphere to the stellar wind. It may thus have a cometary tail

Whaddya get when you cross a planet with a comet? Well, HD 209458b looks like a candidate. It’s a gas giant planet also called Osiris, and it’s orbiting so close to its star that some of its atmosphere gets blown away by the stellar wind. Astronomers¹ think that it may then have a tail like a comet’s.

The researchers studied the odd object using the Hubble Space Telescope and reported their finding in the July 10th issue of The Astrophysical Journal.

The planet is about 153 light-years from Earth, and weighs a bit less than Jupiter. But its zippy orbit is a hundred times closer to its star than Jupiter’s is.

Astronomers got information about the planet by observing its effect on its star’s light when it moved in front of the star from our point of view. They found that most of the gas being driven away from the planet by its star was moving at 22,000 miles per hour. But don’t worry about the planet disappearing entirely² any time soon. The current best estimate to complete the vaporization: a trillion years.
 

1 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

2 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。