又拍下了一颗系外行星（图）

又拍下了一颗系外行星（图）   

这张合成的红外线图片显示：这个暗淡的斑点被认为是一颗行星，正在围绕着绘架座β星旋转（图片的中心是绘架座β星），在这个拥有行星的恒星系统周围，显现出一个由碎物质构成的圆盘。

Another Extrasolar Planet Possibly Imaged

Astronomers say they have directly imaged a giant exoplanet orbiting its parent star. The announcement comes on the heels of two other reports this month of direct images of planets beyond our solar system.	天文学家们称：他们直接拍下了一颗围绕主恒星旋转的巨大行星。此前不久，本月发布的两则其他报道，曾经报道过直接拍下的系外行星。
The new infrared image shows the object as a speck of light near the star Beta Pictoris, which is 70 light-years from Earth,  toward the constellation Pictor.	这张新的红外线图片显示，该物体就象一个光点位于绘架座β星附近。绘架座β星距地球70光年，位于绘架座。
"We cannot yet rule out definitively, however, that the candidate companion could be a foreground or background object," said study team member Gael Chauvin of Grenoble Observatory in France. "To eliminate this very small possibility, we will need to make new observations that confirm the nature of the discovery."	“然而，我们还没有最后排除这种可能性：这颗候选星体是前景或背景上的物体，”研究小组成员、法国格勒诺布尔天文台的盖尔·乔温说，“为了排除这种微乎其微的可能性，我们需要进行新一轮观察，以证实该发现的本质。”
Chauvin and other French astronomers discovered the candidate planet using the European Southern Observatory's (ESO) Very Large Telescope. The possible planet is estimated to weigh about eight times the mass of Jupiter with an orbit of eight astronomical units (AU) from its star, where one AU is the average Earth-sun distance.	乔温和法国其他天文学家们利用欧洲南方天文台的甚大望远镜发现了这颗候选行星。据估计，这颗潜在的行星大约为木星质量的8倍，轨道跟其恒星的距离为8天文单位（1天文单位相当于地球到太阳的平均距离）。
Astrophysicist Sara Seager of MIT, who was not involved in the latest discovery, said while the possibility is exciting, another more convincing image of the object is in order. "We want to make sure it's moving together with the star," Seager said.	麻省理工学院的天体物理学家萨拉·西格没有参与这项最新发现，但她说：存在行星的可能性令人兴奋，同时已经准备好为该物体再拍摄一张更加令人信服的图片。“我们想确定，该物体是随其恒星一起运动的，”西格说。
Another image would show whether the star is moving at a different speed relative to this object and other background objects or if the star and planet are moving together (which would help to confirm this is indeed a planet).	另外一张图像将会显示：相对于该物体和其他背景目标来说，这个这颗恒星是正在以不同的速度运动，还是正在跟该物体一起运动（如果一起运动说明该物体确实是颗行星）。
Astronomers had thought a planet could be responsible for irregularities seen in the debris disk, first imaged in 1994, surrounding Beta Pictoris. As a planet treks around its star, the planet jostles and tugs on pieces of dust and debris, shaping the disk.	1994年，首先拍下了绘架座β星周围的零碎物质圆盘，其形状是不规则的。天文学家们早就认为行星是造成不规则形状的原因。当一颗行星艰难地运行在其恒星周围的时候，对周围的尘埃和碎片产生推挤和拖拽作用，决定了圆盘的形状。
"Beta Pic has been teasing astronomers for the past two decades with hints of an orbiting planet," said University of California, Berkeley, astronomer Paul Kalas, who was not directly involved with the study. Kalas led a team of astronomers who reported this month the first visible-light snapshot of a single-planet system around the star Fomalhaut.	“在过去的二十年中，绘架座β星一直在戏弄天文学家们，一直拥有行星环绕的迹象，”加州大学伯克利分校的天文学家保罗·卡拉斯说。卡拉斯没有直接参与这项研究，但他曾经带领一组天文学家搞研究，他们在本月报道了首个单一行星系统的可见光快照，该系统位于恒星“北落师门”周围。
The researchers say the object does explain the warped disk. "The candidate companion has exactly the mass and distance from its host star needed to explain all the disk's properties," said team leader Anne-Marie Lagrange of the Grenoble Observatory.	研究人员称，该物体确实能够解释这个变形的圆盘。“这颗候选星体的质量及其距主恒星的距离恰好可以解释这个圆盘的一切特性，”研究小组组长、格勒诺布尔天文台的安妮-玛丽·拉格朗日说。
The team tried to rule out other non-planet possibilities. For instance, they looked at images taken by the Hubble Space Telescope of the system, which would likely reveal background and foreground objects. They also used three independent detection methods to rule out the possibility that the point source of light was just an artifact of the observing instrument.	研究小组努力排除其他非行星的可能性。例如，他们观察了哈勃太空望远镜所拍下的该系统的图片，这些图片会显示出背景物体和前景物体。他们还利用三个独立的检测方法，排除了该光点只不过是观察仪器上人造斑点的可能性。
"Overall, this is an exciting discovery that could be verified in just a few weeks time since Beta Pictoris is a bright star visible during the winter months," Kalas told SPACE.com.	卡拉斯告诉太空网的记者说：“总之，这是一个令人兴奋的发现，可能用不了几周的时间就可以得到验证，因为绘架座β星是一颗明亮的恒星，在冬季的几个月里可以看得到。”
Actually, Lagrange said the planet might not be visible with their instruments currently, because of the inclination of the orbit and how it is aligned. So from our perspective on Earth, the planet could travel too close to its star to be visible.	拉格朗日称：事实上，由于轨道的倾斜和该行星的排列情况，目前利用他们的仪器可能看不到这颗行星。因而从我们地球的角度看去，这颗行星的运行轨道可能离其恒星太近，无法看到。
The discovery will be detailed in a forthcoming letter to the editor in the journal Astronomy and Astrophysics.	该发现的详细情况将要寄给《天文学和天体物理学》杂志的编辑，并将发表在该杂志上。