2025年9月10日
The Great Lacerta Nebula
Image Credit & Copyright: Ian Moehring & Kevin Roylance
Explanation: It is one of the largest nebulas on the sky — why isn’t it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta). The emission nebula is difficult to see with wide-field binoculars because it is so faint, but also usually difficult to see with a large telescope because it is so great in angle — spanning about three degrees. The depth, breadth, waves, and beauty of the nebula — cataloged as Sharpless 126 (Sh2-126) — can best be seen and appreciated with a long duration camera exposure. The featured image is one such combined exposure — in this case taken over three nights in August through dark skies in Moses Lake, Washington, USA. The hydrogen gas in the Great Lacerta Nebula glows red because it is excited by light from the bright star 10 Lacertae, one of the bright blue stars just to the left of the red-glowing nebula’s center. Most of the stars and nebula are about 1,200 light years distant.
Jigsaw Universe: Astronomy Puzzle of the Day
Tomorrow’s picture: shadow play
巨大的蜥蜴座星云
影像提供与版权: Ian Moehring & Kevin Roylance
说明: 这是天空中最大型的星云之一——但为何却鲜为人知？它在视角上与大小相近，位置位于蜥蜴座方向，因此被称为「大天蜥星云」。然而，这个发射星云并不容易观测：在广角双筒望远镜下因亮度微弱而难以看清，而在大型望远镜中又因角度过大（横跨约三度）而难以完整呈现。这片星云的深度、广阔、波纹结构与壮丽之美——在星云目录中被编为Sharpless 126 （Sh2-126）——适合透过长时间曝光的的天文摄影来欣赏。这张展示影像便是经过三晚曝光所合成的成果，拍摄于美国 华盛顿州 摩西湖的漆黑夜空下。大天蜥星云中的氢气因受到明亮蓝星10 Lacertae的激发而发出红光，这颗蓝星位于星云红光中心左侧。大部分星云与恒星的距离约为1,200光年。
拼图宇宙: 每日天文学谜题
明日的图片: shadow play
