奎宿九之魂

2021年10月28日

Mirach’s Ghost
Image Credit & Copyright: John Chumack

Explanation: As far as ghosts go, Mirach’s Ghost isn’t really that scary. Mirach’s Ghost is just a faint, fuzzy galaxy, well known to astronomers, that happens to be seen nearly along the line-of-sight to Mirach, a bright star. Centered in this star field, Mirach is also called Beta Andromedae. About 200 light-years distant, Mirach is a red giant star, cooler than the Sun but much larger and so intrinsically much brighter than our parent star. In most telescopic views, glare and diffraction spikes tend to hide things that lie near Mirach and make the faint, fuzzy galaxy look like a ghostly internal reflection of the almost overwhelming starlight. Still, appearing in this sharp image just above and to the right of Mirach, Mirach’s Ghost is cataloged as galaxy NGC 404 and is estimated to be some 10 million light-years away.

Tomorrow’s picture: just the dust

奎宿九之魂
影像提供与版权: John Chumack

说明: 以鬼魂的标准来看，奎宿九之魂其实惊吓度并不高。事实上，奎宿九之魂是个天文学家很熟悉的模糊黯淡星系，它之所以得名，只是恰好出现在亮星奎宿九的视线方向附近而已。在这片星场中心的天体就是奎宿九，它亦名为仙女座β星。离我们大约200光年远的奎宿九，是一颗红巨星，表面温度比太阳低，不过体积远比大阳大，也因此其真实亮度也远大于太阳。在大多数的望远镜影像里，奎宿九炫目的星光和它产生的绕(衍)射星芒，常遮住它附近的天体，也让这个黯淡模糊的星系，看起像是镜筒内反射炫光所产生的鬼影。不过在这幅清晰的影像里，它以弥漫光斑之姿出现奎宿九的右上方。奎宿九之魂的编录号是NGC 404，距离我们大约有一千万光年远。 （Mirach’s Ghost 奎宿九之魂）

明日的图片: just the dust