NASA 美国宇航局的每日一图 3月份
发布: 2009-1-14 17:53 | 作者: webmaster | 来源: 本站原创 | 查看: 187次
2008 March 25 
影像版权与提供: Vicent Peris (OAUV / PTeam), MAST, STScI, AURA, NASA
说明: 隔着星际空间凝视着我们的猫眼星云，距离地球有三千光年远。地球天空中最著名的行星状星云之一的猫眼星云，编录号是NGC 6543，大小约有半光年，为一颗类似太阳恒星生命周期中，最后、短暂但灿烂的谢幕式。这个行星状星云内，即将死亡的中心星，可能在一系列规律的爆发中，不停地拋掷出外层物质，因此形成了星云外围同心圆状的尘埃壳。不过，形态较复杂的美丽内围结构之成因，现在仍未能全盘了解。和哈伯太空望远镜著名的猫眼星云影像比起来，上面这张影像最大的差异是影像后制处理的方法不同，使用更复杂的配色表，以提升影像的清晰度，以及淡色和暗色区域细微构造的可分办度，因此也呈现了不同风貌的猫眼星云。借着探索猫眼星云，天文学家也等于看见我们太阳的宿命，将来，它也会演化到行星状星云阶段，只不过，这还得再等五十亿年。
Explanation: On the left, surrounded by blue spiral arms, is spiral galaxy M81. On the right marked by red gas and dust clouds, is irregular galaxy M82. This stunning vista shows these two mammoth galaxies locked in gravitational combat, as they have been for the past billion years. The gravity from each galaxy dramatically affects the other during each hundred million-year pass. Last go-round, M82's gravity likely raised density waves rippling around M81, resulting in the richness of M81's spiral arms. But M81 left M82 with violent star forming regions and colliding gas clouds so energetic the galaxy glows in X-rays. In a few billion years only one galaxy will remain.
Explanation: On the left, surrounded by blue spiral arms, is spiral galaxy M81. On the right marked by red gas and dust clouds, is irregular galaxy M82. This stunning vista shows these two mammoth galaxies locked in gravitational combat, as they have been for the past billion years. The gravity from each galaxy dramatically affects the other during each hundred million-year pass. Last go-round, M82's gravity likely raised density waves rippling around M81, resulting in the richness of M81's spiral arms. But M81 left M82 with violent star forming regions and colliding gas clouds so energetic the galaxy glows in X-rays. In a few billion years only one galaxy will remain.
