charles 2009-3-27 10:53
加泰隆尼亞上空的麥克諾特彗星
Comet McNaught Over Catalonia
[img]http://i9.tinypic.com/2ecq8f8.jpg[/img]
影像提供與版權: Juan Casado
[color=navy]Explanation: [/color]
[color=dimgray]The second weekend of January, 2007, Comet McNaught peaked at a brightness that surpassed even Venus. Fascinated sky enthusiasts in the Earth's northern hemisphere were treated to an instantly visible comet head and a faint elongated tail near sunrise and sunset. Recent brightness estimates had Comet McNaught brighter than magnitude -5 (minus five) over this past weekend, making it the brightest comet since Comet Ikeya-Seki in 1965, which was recorded at -7 (minus seven). The Great Comet of 2007 reached its brightest as it rounded the Sun well inside the orbit of Mercury. Over the next week Comet McNaught will begin to fade as it moves south and away from the Sun. The unexpectedly bright comet should remain visible to observers in the southern hemisphere with unaided eyes for the rest of January. The above image, vertically compressed, was taken at sunset last Friday from mountains above Catalonia, Spain. [/color]
[color=navy]說明:[/color]
[color=dimgray]2007年一月的第二個週末，麥克諾特彗星亮度激增，甚至比金星還亮。北半球的眾多天文迷在黃昏和清晨爭睹這顆擁有肉眼可見的彗核以及細長的彗尾的彗星。最新的亮度估計顯示出，麥克諾特彗星的亮度已經比-5星等還亮，這是自1965年池谷-關彗星 (記錄上的亮度是-7星等)以來最明亮的一顆彗星。當這顆2007年的大彗星運行到比水星軌道更接近太陽時，它的亮度達到最大值。 接下來的這一週，麥克諾特彗星將慢慢由南方遠離太陽，並開始變暗。在一月底之前，這顆彗星仍然保持著肉眼可見的亮度，但是只有南半球的人可以觀測得到它。上圖是經過縱向壓縮的影像，原始影像是在一月12日拍攝的，拍攝地點位於西班牙 加泰隆尼亞的山上。 [/color]
[size=2]資料來源: Scientific American
skylook
Department of Physics, NCKU[/size][color=white][size=1]
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