2024年09月02日:悬在太阳上方的三角形日珥-（A Triangular Prominence Hovers Over the Sun） 2024年09月02日:悬在太阳上方的三角形日珥-（A Triangular Prominence Hovers Over the Sun）--原图下载{mtitle title="悬在太阳上方的三角形日珥"/}Image Credit & Copyright: Andrea Vanoni说明: 为何有个三角形悬在太阳的上方？虽然它的形状不寻常，但这种结构却颇为常见，因为它就是不断演化的日珥。太阳表面的环状磁场会导引高能粒子的流动，有时也会拘束发光气体，并让它悬浮在空中达数个月之久。日珥之所以很明亮，则是因为它的内部有极为炽热、密度高到不透光的太阳电浆/等离子体。这个出现在上星期的吸睛三角日珥，其实比地球大。这个从形成到爆发大约只有1天就消失的日珥，除了由几位太阳摄影者为它留下影像之外，也由美国航太总署的太阳动态观测卫星加以记录。这幅主题影像摄于明亮的氢 红光波段。在日珥的下方，可见到形似绒毛地毯的太阳色球层，而背景天空则极为昏暗，看不到任何星星。最后，今年的太阳表面格外的活跃。{lamp/}原文：{mtitle title="A Triangular Prominence Hovers Over the Sun"/}Image Credit & Copyright: Andrea VanoniExplanation: Why is there a triangle hovering over the Sun? Although the shape is unusual, the type of structure is not: it is part of an evolving solar prominence. Looping magnetic fields on the Sun channel the flow of energetic particles, sometimes holding glowing gaseous structures aloft for months. A prominence glows brightly because it contains particularly hot, dense, or opaque solar plasma.The surprising triangular structure occurred last week.Larger than our Earth, the iconic prominence was imaged by several solar photographers and documented by NASA's Solar Dynamic Observatory to form and violently dissipate in about a day.The featured image was captured in a color of red light emitted strongly by hydrogen. Below, solar fibrils carpet the Sun's chromosphere, while the background sky is so faint in comparison that no stars are visible. Our Sun's surface has been quite active this year.

2024年08月14日:德国上空的流星与极光-（Meteors and Aurora over Germany） 2024年08月14日:德国上空的流星与极光-（Meteors and Aurora over Germany）--原图下载{mtitle title="德国上空的流星与极光"/}Image Credit & Copyright: Chantal Anders说明: 这是个不寻常的夜晚。首先，这星期稍早从8月11日过渡到12日的这个夜晚，落在英仙流星雨的极大期附近。因此，当来自斯威福特-塔托彗星的碎片穿入地球的大气层时，就会产生划过长空的流星。而更不寻常的是，德国中部的夜空，甚至会发出紫色的辉光。这种红蓝色的辉光，则是数天前由太阳喷出的大群粒子所诱发的极光。此次的极光磁暴极为强烈，就连在北半球的美国德州及意大利都能看到极光。这幅摄于德国 恩瑟镇的精彩主题影像，是由在26分钟期间拍摄的7张照片叠合而成。英仙流星雨每年的8月都会如期降临，但要在这么偏南的地点见到极光，不但罕见而且难以预测{lamp/}原文：{mtitle title="Meteors and Aurora over Germany"/}Image Credit & Copyright: Chantal AndersExplanation: This was an unusual night.For one thing, the night sky of August 11 and 12, earlier this week, occurred near the peak of the annual Perseid Meteor Shower.Therefore, meteors streaked across the dark night as small bits cast off from Comet Swift-Tuttle came crashing into the Earth's atmosphere.Even more unusually, for central Germany at least, the night sky glowed purple.The red-blue hue was due to aurora caused by an explosion of particles from the Sun a few days before.This auroral storm was so intense that it was seen as far south as Texas and Italy, in Earth's northern hemisphere. The featured image composite was built from 7 exposures taken over 26 minutes from Ense, Germany.The Perseids occur predictably every August, but auroras visible this far south are more unusual and less predictable.

2024年03月10日:世界尽头的日全食-（A Total Eclipse at the End of the World） 2024年03月10日:世界尽头的日全食-（A Total Eclipse at the End of the World）--原图下载{mtitle title="世界尽头的日全食"/}Image Credit & Copyright: Fred Bruenjes(moonglow.net)说明: 为了看日全食，你愿意专程到世界的尽头吗？如果答案是肯定的，你会意外有人比你早到吗？在2003年的南极洲日全食之时，太阳、月亮和二位摄影师全都在南极洲列队。即使是地点极端偏僻，还是有一群日食热爱族，勇闯世界的底部，以体验太阳消失在月亮后方的短暂超现实感，而上面这幅主题影像就是他们的珍藏之一。影像是由4张数位照片组合而成，以模拟人类肉眼调适之后所见到的日食景观。拍照时，月亮与太阳刚好悬在南极一座山脊的上方。在突然降临的黑暗里，肉眼可见到镶在月亮边缘的壮丽日冕。他们所拍摄的众多影像之一，很意外地拍到一位正在检查相机的拍照者，而他的左边则放着随身的装备袋与摺叠椅。一例较轻鬆就可见的日食将在4星期之内发生，可见区域为穿过北美洲的一道颀长而狭窄的食带。{lamp/}原文：{mtitle title="A Total Eclipse at the End of the World"/}Image Credit & Copyright: Fred Bruenjes(moonglow.net)Explanation: Would you go to the end of the world to see a total eclipse of the Sun?If you did, would you be surprised to find someone else there already?In 2003, the Sun, the Moon, Antarctica, and two photographers all lined up inAntarctica during an unusualtotal solar eclipse. Even given the extreme location, a group ofenthusiastic eclipse chasers ventured near thebottom of the world toexperience the surreal momentarydisappearance of the Sun behind the Moon. One of the treasures collected was thefeatured picture -- a composite of four separate imagesdigitally combined to realistically simulate how the adaptive humaneye saw the eclipse. As the image was taken, both theMoon and the Sunpeeked together over an Antarctic ridge. In thesudden darkness, themagnificent coronaof the Sun became visible around the Moon. Quite by accident, another photographer was caughtin one of the images checking his video camera. Visible to his left are an equipment bag and acollapsible chair. A more easily visible solar eclipse will occur in just underfour weeks and be visible from a long, thin swath of North America.

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.

2024年01月04日:天市右垣十一：速逃星-（Zeta Oph: Runaway Star） 2024年01月04日:天市右垣十一：速逃星-（Zeta Oph: Runaway Star）--原图下载{mtitle title="天市右垣十一：速逃星"/}Image Credit: NASA, JPL-Caltech,Spitzer Space Telescope说明: 在这幅令人讚叹的红外光影像里，速逃星天市右垣十一就像一艘滑过宇宙海之船舰，产生了这道弓形震波。在这张假色影像中心附近，质量大约是20倍太阳的泛蓝天市右垣十一，正以每秒24公里的速度向左飞奔。 它前方强烈的恒星风，挤压并加热富含尘埃的星际物质，造成了这道弓形震波前沿。为何这颗恒星会高速运动呢？天市右垣十一原来可能是双星系统的成员之一，质量大于它的伴星之寿命较短，当这颗伴星发生超新星爆炸、耗损质量的同时，天市右垣十一也被抛出这个系统。位于蛇夫座方向的天市右垣十一，离我们约460光年远。它的光度约莫是太阳的65,000倍，所以如果不是周围包裹着遮光的尘埃，它会是地球夜空的亮星之一。以天市右垣十一的距离来换算，这幅宽约1.5度的影像，跨幅约有12光年。在2020年1月，美国航太总署让史匹哲太空望远镜进入安全沉睡模式，终结了它16年来探索宇宙的成功任务。 (Zeta Oph, Zeta Ophiuchi 天市右垣十一、韩){lamp/}原文：{mtitle title="Zeta Oph: Runaway Star"/}Image Credit: NASA, JPL-Caltech,Spitzer Space TelescopeExplanation: Like a ship plowing through cosmic seas,runaway star Zeta Ophiuchiproduces the arcing interstellar bow wave or bow shock seen in this stunning infrared portrait.In the false-color view, bluish Zeta Oph, a star about 20 times moremassive than the Sun, lies near the center of the frame, movingtoward the left at 24 kilometers per second.Its strong stellar wind precedes it, compressing and heating the dustyinterstellar materialand shaping the curved shock front.What set this star in motion?Zeta Oph was likely once a member of abinary star system, itscompanion star was more massive and hence shorter lived.When the companionexploded as a supernovacatastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Ophis 65,000 times more luminous than theSun and would be one of the brighter starsin the sky if it weren't surrounded by obscuring dust.The image spans about 1.5 degrees or 12 light-yearsat the estimated distance ofZeta Ophiuchi.In January 2020, NASA placed the Spitzer Space Telescope in safe mode, ending its 16 successful yearsofexploring the cosmos.

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.