2024年01月22日:山与月的影子-（Shadows of Mountain and Moon） 2024年01月22日:山与月的影子-（Shadows of Mountain and Moon）--原图下载{mtitle title="山与月的影子"/}Image Credit & Copyright: Enzo Massa Micon说明: 月亮和山会投下类似的影子吗？会的，但它们的明暗界线并不一定要对齐。上图所呈现的为2022年10月初，悬在义大利 格里沃拉山上空的上弦月。在这幅优美的主题影像里，位于右方的太阳，同时照亮了月亮及山峰的右侧。这种月相之所以有“上弦”之称，则是因为从地球看出去，被阳光照亮的月面之可见比例为4分之1。而所拍下的单曝光影像，更经过后置处理以突显影像中的这2个巨大物体。由于每天地球自转一圈，因此要拍下上弦月的明暗界线和笔直山脊几乎对齐的画面，拍照的时间点必需抓得很精准。{lamp/}原文：{mtitle title="Shadows of Mountain and Moon"/}Image Credit & Copyright: Enzo Massa MiconExplanation: Can the Moon and a mountain really cast similar shadows?Yes, but the division between light and dark does not have to be aligned.Pictured, a quarter moon was captured above the mountain Grivola in Italy in early October of 2022. The Sun is to the right of the featured picturesque landscape, illuminating the right side of the Moon in a similar way that it illuminates the right side of the mountain.This lunar phase is called "quarter",in part, because the lit fraction visible from Earth is one quarter of the entire lunar surface. Digital post-processing of this single exposure gave both gigantic objects more prominence.Capturing the terminator of this quarter moon in close alignment with nearly vertical mountain ridge required careful timing because the Earth rotates once a day.

2023年12月24日:NGC 2440: 新白矮星的茧-（NGC 2440: Cocoon of a New White Dwarf） 2023年12月24日:NGC 2440: 新白矮星的茧-（NGC 2440: Cocoon of a New White Dwarf）--原图下载{mtitle title="NGC 2440: 新白矮星的茧"/}Image Credit: NASA, ESA, Hubble;Processing: H. Bond (STScI), R. Ciardullo (PSU), Forrest Hamilton (STScI)说明: 这幅影像中心的天体是什么？就像蝴蝶一样， 白矮星也会抛开包裹自己的气体茧，“破茧而出" 开启另一段生命之旅。在这种类比中，我们的太阳会是毛毛虫，而被抛出的气壳为最美丽的蝴蝶。上图里的"茧”是名为NGC 2440的行星状星云<a/>，它的内部有目前所知最炽热的白矮星之一。而在这张影像中心附近的橙色亮斑，即为这颗白矮星。我们的太阳再过五十亿年，也会变成一只 "白矮星蝴蝶"。{lamp/}原文：{mtitle title="NGC 2440: Cocoon of a New White Dwarf"/}Image Credit: NASA, ESA, Hubble;Processing: H. Bond (STScI), R. Ciardullo (PSU), Forrest Hamilton (STScI)Explanation: What's that in the center? Like a butterfly, a white dwarf star begins its life by casting off a cocoon of gas that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest cocoon of all. In the featured cocoon, the planetary nebula designated NGC 2440 contains one of the hottest white dwarf stars known. The white dwarf can be seen as the bright orange dot near the image center. Our Sun will eventually become a white dwarf butterfly, but not for another 5 billion years.

2023年12月19日:NGC 1499：加州星云-（NGC 1499: The California Nebula） 2023年12月19日:NGC 1499：加州星云-（NGC 1499: The California Nebula）--原图下载{mtitle title="NGC 1499：加州星云"/}Image Credit & Copyright: Steven Powell说明: 太空中难道真的有卡拉菲亚女王的神话岛屿吗？或许没有，不过这团分子云的轮廓，倒真的形似美国的加州。而我们位在银河猎户臂里的太阳，离加州星云大约只有1,000光年远。亦名为NGC 1499的这团经典发射星云，长度约有100光年。在这幅主题影像里，加州星云最醒目的泛红色泽，来自氢原子被高能星光电离后后，氢离子和失去的电子复合时所发出的特徵红光。而发出高能星光 电离大部分云气的恒星，极可能是位于星云右侧的明亮炽热色泽泛蓝的卷舌三（英仙座Xi星）。经常是天文摄影者拍照目标的加州星云，在幽暗的天空下，用大视野望远镜即可在英仙座方向离昴宿星团不远处找到它。{lamp/}原文：{mtitle title="NGC 1499: The California Nebula"/}Image Credit & Copyright: Steven PowellExplanation: Could Queen Calafia's mythical island exist in space?Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA.Our Sun has its home within the Milky Way'sOrionArm, only about 1,000 light-years from the California Nebula.Also known as NGC 1499, the classic emission nebula is around 100 light-years long.On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with longlost electrons, stripped away (ionized) by energetic starlight.The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Perseijust to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark skytoward the constellation of Perseus, not far from the Pleiades.

2023年12月11日:太阳极小期与太阳极大期-（Solar Minimum versus Solar Maximum） 2023年12月11日:太阳极小期与太阳极大期-（Solar Minimum versus Solar Maximum）--原图下载2023 December 11 {mtitle title="太阳极小期与太阳极大期"/}Video Credit: NASA,SDO, SVS说明: 太阳表面不停的在变。它有些年分很宁静，出现相对少量的太阳黑子和活跃区。而在其他的年分，太阳表面会剧烈翻腾，出现大量的太阳黑子，并经常发生日冕物质抛射和日闪（耀斑）。太阳表面因为对磁学性质的改变作出反应，每11年，会经历一次相对平静的太阳极小期及一次相对动荡的极大期。左侧主题影片所呈现的是2019年底的一个月，当时太阳处在极小期附近，右侧则是2014年的一个月，太阳处在极大期附近。这部影片是由美国航太总署的太阳动态观测卫星（SDO）摄于远紫外光 波段。太阳正在向2025年的极大期迈进，不过即使是现在，太阳表面已出现令人惊讶的高活动量。{lamp/}原文：{mtitle title="Solar Minimum versus Solar Maximum"/}Video Credit: NASA,SDO, SVSExplanation: The surface of our Sun is constantly changing. Some years it is quiet, showing relatively few sunspots and active regions.Other years it is churning, showing many sunspots and throwing frequent Coronal Mass Ejections (CMEs) and flares.Reacting to magnetism, our Sun's surface goes through periods of relative calm, called Solar Minimum and relative unrest, called Solar Maximum, every 11 years.The featured video shows on the left a month in late 2019 when the Sun was near Solar Minimum, while on the right a month in 2014 when near Solar Maximum. The video was taken by NASA's Solar Dynamic Observatory in far ultraviolet light.Our Sun is progressing again toward Solar Maximum in 2025, but displaying even now a surface with a surprisingly high amount of activity.

2023年11月12日:瑞典山峰后方的凸月-（Gibbous Moon beyond Swedish Mountain） 2023年11月12日:瑞典山峰后方的凸月-（Gibbous Moon beyond Swedish Mountain）--原图下载{mtitle title="瑞典山峰后方的凸月"/}Image Credit & Copyright: Göran Strand说明: 这是一轮凸月。对很多地球人来说，更熟悉的是整个月面都受太阳照亮的满月，或是月面只有一抹日曜银白的蛾眉月。而盈踰半满月面，而又逊于满月的月相，则是凸月。鲜少出现在电视和电影的凸月，其实是夜空很常见的景观。这幅主题影像，是在2018年10月底左右摄于瑞典．耶姆特兰。这轮凸月在数天后，变成下蛾眉月，接着成为新月，再过数天后，又变身为上蛾眉月。摄影者原先的意图是要拍摄美丽的凸月景观，却很意外的捕捉到一部显然近在前方，却看似从月轮上方掠过的飞机。{lamp/}原文：{mtitle title="Gibbous Moon beyond Swedish Mountain"/}Image Credit & Copyright: Göran StrandExplanation: This is a gibbous Moon.More Earthlings are familiar with a full moon, when the entire face of Luna is lit by the Sun, and a crescent moon, when only a sliver of the Moon's face is lit. When more than half of the Moon is illuminated, though, but still short of full illumination, the phase is called gibbous. Rarely seen in television and movies, gibbous moons are quite common in the actual night sky.The featured image was taken in Jämtland, Sweden near the end of 2018 October.That gibbous moon turned, in a few days, into a crescent moon, and then a new moon, then back to a crescent, and a few days past that, back to gibbous. Setting up to capture a picturesque gibbous moonscape, the photographer was quite surprised to find an airplane, surely well in the foreground, appearing to fly past it.

2023年11月06日:义大利上空的红色极光-（Red Aurora over Italy） 2023年11月06日:义大利上空的红色极光-（Red Aurora over Italy）--原图下载{mtitle title="义大利上空的红色极光"/}Image Credit & Copyright: Giorgia Hofer说明: 昨晚出现在地平线上方的泛光辉光是什么？极光。数天前，我们格外活跃的太阳发生了一次表面爆发，并喷出一大团电子、质子和更重的带电原子核。这例日冕物质抛射（CME）触发了地球上的极光，而据报导，就连在地球北半球很靠南的地区，也能见到极光。举例来说，这位义大利 天文摄影者，即是生平首次在该国拍到极光。此外，在许多记录这些极光的影像里，极光的色泽极红。在这幅摄于义大利阿尔卑斯山中，以上科梅利科镇为前景的主题影像里，可见到我们银河系的中央盘面从左下角升起。然而，其中最吸睛的还是右缘的鲜红极光。这张主题影像，是由同一部相机在相同位置连续拍摄的前景和背景照片组合而成。{lamp/}原文：{mtitle title="Red Aurora over Italy"/}Image Credit & Copyright: Giorgia HoferExplanation: What was that red glow on the horizon last night?Aurora.Our unusually active Sun produced a surface explosion a few days ago that sent out a burst of electrons, protons, and more massive charged nuclei.This coronal mass ejection (CME) triggered auroras here on Earth that are being reported unusually far south in Earth's northern hemisphere. For example, this was the first time that the astrophotographer captured aurora from her home country of Italy.Additionally, many images from these auroras appear quite red in color. In the featured image, the town of Comelico Superiore in the Italian Alps is visible in the foreground, with the central band of our Milky Way galaxy seen rising from the lower left.What draws the eye the most, though, is the bright red aurora on the far right.The featured image is a composite with the foreground and background images taken consecutively with the same camera and from the same location.