Pleiades: The Seven Sisters Star Cluster
Image Credit & Copyright: Blake Estes (iTelescope Siding Spring Obs.) & Christian Sasse
Explanation: Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen with the unaided eye even from the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured 11-hour exposure, taken from the Siding Spring Observatory in Australia, covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six of the sister stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer’s eyesight.
Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)
Tomorrow’s picture: star birth mountain
影像提供与版权: Blake Estes (iTelescope Siding Spring Obs.) & Christian Sasse
说明: 你看过昴宿星团吗？即使你看过，但可能也不曾见过它这付既大又清晰的模样。昴宿星团或许是天空中最著名的星团，即使在有光害的城市中心里，不需借助双筒望远镜也能看到星团内的亮星。如果在远离光害的地点进行长时间曝光取像，围拱着昴宿 星团成员星的尘埃就会变得非常醒目。而这张摄于澳洲塞汀泉天文台，跨幅约数个满月宽度的11小时长曝光主题影像即可为佐证。昴宿星团又名为七姐妹星团或M45，位在金牛座方向约400光年远之处。一则带点现代转折的传说宣称：在星团命名后，最亮的数颗星之一暗去，让星团只剩下6颗肉眼可见的亮星。然而，昴宿星团可见的星数可多于或少于7颗，端视观测者的视力与星空的幽暗程度而异。
明日的图片: star birth mountain