2026年2月19日
IC 2574: Coddington’s Nebula
Image Credit & Copyright: Dane Vetter
Explanation: Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small, irregular galaxies form stars too. In fact, dwarf galaxy IC 2574 shows clear evidence of intense star forming activity in its telltale reddish regions of glowing hydrogen gas. Just as in spiral galaxies, the turbulent star-forming regions in IC 2574 are churned by stellar winds and supernova explosions spewing material into the galaxy’s interstellar medium and triggering further star formation. A mere 12 million light-years distant, IC 2574 is part of the M81 group of galaxies, seen toward the northern constellation Ursa Major. Also known as Coddington’s Nebula, the faint but intriguing island universe is about 50,000 light-years across, discovered by American astronomer Edwin Coddington in 1898.
Tomorrow’s picture: in the dark
IC 2574: 柯丁顿星云
影像提供与版权: Dane Vetter
说明: 宏伟螺旋星系似乎总是备受瞩目，它们年轻、明亮、呈蓝色的星团在美丽对称的螺旋臂中熠熠生辉。但小型不规则星系也会形成恒星。事实上，矮星系IC 2574在其标志性的红色发光氢气区域中，清晰地展现了剧烈恒星形成活动的证据。正如螺旋星系一样，IC 2574中湍流的恒星形成区域也受到恒星风和超新星爆发的搅动，这些爆发将物质喷射到星系的星际介质中，并进一步触发更多恒星的形成。IC 2574距离我们仅约1,200万光年，是位于北天大熊座方向的M81星系群的一部分。这个暗淡但引人入胜的宇宙岛屿，又称科丁顿星云，直径约50,000光年，由美国天文学家埃德温·科丁顿于1898年发现。
明日的图片: in the dark
