2017年11月03日: A/2017 U1: 星际访客-(A/2017 U1: An Interstellar Visitor)

2017年11月03日: A/2017 U1: 星际访客-(A/2017 U1: An Interstellar Visitor)

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2017-11-03 / 0 评论 / 0 阅读 / 正在检测是否收录...

2017年11月03日: A/2017 U1: 星际访客-(A/2017 U1: An Interstellar Visitor)
2017年11月03日: A/2017 U1: 星际访客-(A/2017 U1: An Interstellar Visitor)--原图下载


Image Credit: Alan Fitzsimmons(ARC,Queen's University Belfast),Isaac Newton Group
说明: 沿着极端双曲线轨道高速前进,并在掠过太阳时转了一个发夹弯的A/2017 U1,是人类第一个确知来自星际空间的小天体。在这幅由加那利群岛.赫歇尔望远镜,于10月28日拍摄的5分钟长曝光影像里,中心处的光点,就是这颗形似小行星而没有彗星行为的星际访客。背景暗星之所以会曳出条状光痕,则是因为这部4.2米口径的望远镜,是以视野中快速移动的A/2017 U1为导星。天文学家Rob Weryk (IfA)是在10月19日,率先从例行性的夜间泛星巡天数据中,注意到这颗移动天体。目前逐渐远去的A/2017,除了永不再返太阳系之外,也只有大口径的地球光学望远镜才得见。虽然根据它的轨道,可判断它是一颗星际天体,但目前仍不知道它能在银河众星之间漂流多久。它的星际行进速率大约是每秒26公里,作为比较,人类发射的航行家1号太空船,在星际空间行进的速率大约是每秒17公里。

原文:

Image Credit: Alan Fitzsimmons(ARC,Queen's University Belfast),Isaac Newton Group
Explanation: Travelingat high velocity along an extreme hyperbolic orbit and makinga hairpin turn as it swung past the Sun,the now designated A/2017 U1 is the first knownsmall body from interstellar space.A point of light centered in this 5 minute exposure recordedwith the William Herschel Telescope in the Canary Islands on October 28, theinterstellar visitor is asteroid-like withnosigns of cometary activity.Faint background stars appear streaked because the massive 4.2 meterdiameter telescope is tracking the rapidly moving A/2017 U1in the field of view.Astronomer Rob Weryk (IfA)firstrecognized the moving object in nightly Pan-STARRS sky surveydata on October 19.A/2017 is presently outbound,never to return tothe Solar System, and already only visiblefrom planet Earthin large optical telescopes.Though an interstellar origin has been established based on its orbit,it is still unknown how long the object could havedrifted among thestars of the Milky Way.But its interstellar cruise speed would be about 26 kilometers persecond.By comparison humanity's Voyager 1 spacecraft travels about 17kilometers per secondthrough interstellar space.

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