2018年12月20日:红星云、绿彗星与蓝恆星-（Red Nebula, Green Comet, Blue Stars）--原图下载
Image Credit &Copyright: Tom Masterson (Grand Mesa Observatory)
说明: 这片嘉年华会般的彩色星空，摄于12月17日的清晨，在维尔塔宁彗星最近距离通过地球附近之后。这颗肉眼勉强可见的彗星，美丽彗发的泛绿色泽，只有在叠加了数张以位在昴宿星团下方的彗星为导星的照片之后，才得以显现出来。这些照片也突显了年轻昴宿星团成员星的蓝色星光，从恒星周围的尘埃云反射之景象。沿着英仙分子云边缘的暗色尘埃云向左扫视，视线会来到名为加州星云的发射星云NGC 1499。这团过于昏暗而肉眼不得见的星云，其鲜明的泛红辉光来自与电子复合的电离氢原子。在12月23日左右，维尔塔宁彗星会运行到御夫座的亮星五车二附近，届时用双筒望远镜就能轻易找到它。
原文：
Image Credit &Copyright: Tom Masterson (Grand Mesa Observatory)
Explanation: Thisfestively colored skyscape was captured in the early morninghours of December 17, followingComet Wirtanen'sclosest approach toplanet Earth.The comet was just visible to the eye.The lovely green color of its fluorescing cometary atmosphereor coma is brought out here only by adding digital exposuresregistered on the comet's position below the Pleiades star cluster.The exposures also bring out blue starlight reflected by thedust clouds surrounding the young Pleiades stars.Gaze (toward the left) across dusty dark nebulae alongthe edge of the Perseus molecular cloud and you'lltravel to emission nebulaNGC 1499, also known as the California nebula.Too faintfor the eye, the cosmic cloud's pronounced reddish glowis from electrons recombining with ionized hydrogen atoms.Around December 23rd, Comet Wirtanen should be easy tofind with binocularswhen it sweeps close to bright star Capellain the northern winter constellation Auriga, the Charioteer.
评论