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    [雙語文摘] 神秘的塵埃消失事件

    The Mysterious Case of the Disappearing Dust



    This artist's concept illustrates a dusty planet-forming disk, similar to the one that vanished around the star called TYC 8241 2652. Image credit: NASA/JPL-Caltech Larger view

    示意圖:這是類似消失的環繞在名為TYC8241 2652恒星周圍的行星構成塵埃。作者:NASA/JPL-Caltech

    Imagine if the rings of Saturn suddenly disappeared. Astronomers have witnessed the equivalent around a young sun-like star called TYC 8241 2652. Enormous amounts of dust known to circle the star are unexpectedly nowhere to be found.

    天文學家已經目睹了在一個年輕的太陽般的恒星(TYC8241 2652)周圍的(行星構成塵埃)的消失。你們可以試想一下,就像土星環突然消失了一樣。已知數量巨大的塵埃如今卻出人意外的消失不見無處可尋。

    "It's like the classic magician's trick: now you see it, now you don't. Only in this case we're talking about enough dust to fill an inner solar system and it really is gone!" said Carl Melis of the University of California, San Diego, who led the new study appearing in the July 5 issue of the journal Nature.


    A dusty disk around TYC 8241 2652 was first seen by the NASA Infrared Astronomical Satellite (IRAS) in 1983, and continued to glow brightly for 25 years. The dust was thought to be due to collisions between forming planets, a normal part of planet formation. Like Earth, warm dust absorbs the energy of visible starlight and reradiates that energy as infrared, or heat, radiation.

    這圍繞TYC8241 2652的塵埃盤最早于1983年被NASA的紅外天文衛星(IRAS)發現,并觀測到它連續25年的發光。這些塵埃被認為是行星成型過程中的正常的組成部分——塵?;ハ嗯鲎材鄣倪^程。像地球一樣,塵埃吸收著可見星光的能量和再輻射例如紅外線,熱量,輻射等。

    The first strong indication of the disk's disappearance came from images taken in January 2010 by NASA's Wide-field Infrared Survey Explorer, or WISE. An infrared image obtained at the Gemini telescope in Chile on May 1, 2012, confirmed that the dust has now been gone for two-and-a-half years.


    "Nothing like this has ever been seen in the many hundreds of stars that astronomers have studied for dust rings," said co-author Ben Zuckerman of UCLA, whose research is funded by NASA. "This disappearance is remarkably fast even on a human time scale, much less an astronomical scale. The dust disappearance at TYC 8241 2652 was so bizarre and so quick, initially I figured that our observations must simply be wrong in some strange way."

    “這樣的事情在過去天文學者對數百個恒星塵埃環的研究中從未見過”合著者加州大學洛杉磯分校的本·朱克曼說(他的研究是NASA資助的),“這種消失是非??斓纳踔猎谌祟惖臅r間尺度上,比一個天文時間單位要小的多(注:眾所周知,天文中時間單位尺度都是很長的)。TYC8241 2652的塵埃盤消失的如此離奇與迅速,以至于我們最初認為可能是我們犯了一些簡單的錯誤。”

    The astronomers have come up with a couple of possible solutions to the mystery, but they say none are compelling. One possibility is that gas produced in the impact that released the dust helped to quickly drag the dust particles into the star and thus to their doom. In another possibility, collisions of large rocks left over from an original major impact provide a fresh infusion of dust particles into the disk, which caused the dust grains to chip apart into smaller and smaller pieces.


    The result is based upon multiple sets of observations of TYC 8241 2652 obtained with the Thermal-Region Camera Spectrograph on the Gemini South telescope in Chile; IRAS; WISE; NASA's Infrared Telescope on Mauna Kea in Hawaii; the European Space Agency's Herschel Space Telescope, in which NASA plays an important role; and the Japanese/European Space Agency AKARI infrared satellite.

    結論的得出是依據智利南雙子望遠鏡遠紅外攝像攝譜儀、IRAS、WISE、夏威夷冒納基的NASA紅外望遠鏡、歐洲航天局赫歇爾太空望遠鏡(NASA主導的)、日本/歐洲航天局Akari號紅外衛星對TYC 8241 2652所獲得的圖像

    原創翻譯:龍騰網 http://www.ltaaa.com 翻譯:武力收復臺灣 轉載請注明出處


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