charles 2009-3-27 10:43
超新星遺骸SN 1987A的擴張迴光
The Expanding Light Echoes of SN 1987A
[img]http://i17.tinypic.com/2w2ho43.gif[/img]
影像提供: The SuperMACHO Team, CTIO, NOAO, NSF
[color=navy]Explanation: [/color]
[color=dimgray]Can you find supernova 1987A? It isn't hard -- it occurred at the center of the expanding bullseye pattern. Although this stellar detonation was first seen almost two decades ago, light from it continues to bounce off clumps of interstellar dust and be reflected to us today. These expanding light echoes have been recorded in the above time-lapse movie recorded over four years from the Blanco 4-meter telescope in Chile. The first image is an image of the SN 1987A region, while the next four images were created by subtracting consecutive images, taken a year apart, and leaving only the difference between the images. Light echoes can be seen moving out from the position of the supernova. The SuperMACHO team who recorded the above light echoes around supernova 1987A has also found faint and previously unnoticed light echoes from two other LMC supernovas. Study of these light echoes has enabled more accurate determinations of the location and date of these two supernova explosions that were first visible hundreds of years ago. [/color]
[color=navy]說明:[/color]
[color=dimgray]你能找到超新星1987A嗎？不會太難，它就在這些擴張環的中心。雖然這次的恆星爆炸是在將近二十年前就被發現了，但爆炸所產生的光不停地被周圍的星際塵埃散射及反射，所以直到現在還能為我們所見。上面這幅時序動畫是由位在智利的四米布藍柯望遠鏡在過去四年所拍攝的，其中可見到三個擴張的迴光圈。第一個定格呈現了SN 1987A所在的區域，接下來的四個定格，是由拍攝時間相隔一年的影像相減並保留它們之間的差異所得結果。從動畫可清楚看到迴光從超新星發生的地點向外傳播。記錄上面這個超新星1987A 迴光影像的SuperMACHO團隊，也找到其他二個大麥哲倫星系超新星以前未曾注意到的昏暗迴光。研究這些迴光，讓天文學家能更精確地決定這二個出現在數百年前的超新星發生之時間和位置。[/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
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