Portrait of NGC 3628 Image Credit: Image Credit & Copyright: Mike Selby & Mark Hanson

Explanation: Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy. It also reveals a small galaxy nearby (below), likely a satellite of NGC 3628, and a very faint but extensive tidal tail. The drawn out tail stretches for about 300,000 light-years, even beyond the left edge of the frame. NGC 3628 shares its neighborhood in the local universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic neighbors are likely responsible for creating the tidal tail, as well as the extended flare and warp of this spiral’s disk. The tantalizing island universe itself is about 100,000 light-years across and 35 million light-years away in the northern springtime constellation Leo.

Tomorrow’s picture: Z is for Mars

星系NGC 3628 影像提供与版权: Mike Selby & Mark Hanson

说明: 在清晰的望远镜影像里，NGC 3628看起来是个鼓胀星系盘受到尘埃带分割的星系。而这幅此宏伟侧向螺旋星系的影像，很自然地让一些天文学家联想到汉堡星系的昵称。这幅影像，同时也呈现了一个可能是NGC 3628伴星系的邻近小星系（下），以及一道广袤但暗淡的潮汐尾。这道绵延约300,000光年的长尾，甚至伸展到这幅大视野影像的左缘之外。NGC 3628和其他二个大螺旋星系M65和M66，共享它们所在的宇宙空间和狮子三重星系的令名。NGC 3628和邻近星系的重力交互作用，可能是造成潮汐尾及星系盘扭曲和突然增亮的主因。这个迷人的宇宙岛，位在北半球春天的狮子座之内，离我们约3千5百万光年远，大小则在10,000光年上下。

明日的图片: Z is for Mars