2024年05月02日:M100：宏伟的螺旋星系-（M100: A Grand Design Spiral Galaxy） 2024年05月02日:M100：宏伟的螺旋星系-（M100: A Grand Design Spiral Galaxy）--原图下载{mtitle title="M100：宏伟的螺旋星系"/}Image Credit &Copyright:Drew Evans说明: 庞大美丽的M100有宏伟螺旋星系的贴切称号。这个庞然的星系，拥有超过1千亿颗成员星；此外，它也酷似我们的银河系，拥有轮廓鲜明的螺旋臂。亦名为NGC 4321的M100，位于后发座方向，离我们约有5千6百万光年远，是室女星系团最明亮的星系成员之一。 在这幅望远镜影像里，这个正向的宏伟螺旋星系，与较不出采的侧向螺旋星系NGC 4312（右上）共享了这片宽将近1度的视野。这张摄于地球亚利桑那州旗桿镇、总曝光时间等同于21小时的影像，突显了M100里的明亮泛蓝星团和错综複杂的蜿蜒尘埃带等，这些螺旋星系的共有标誌性特徵。 量测星系M100里的变星，对测定宇宙的大小和年龄有重要贡献。{lamp/}原文：{mtitle title="M100: A Grand Design Spiral Galaxy"/}Image Credit &Copyright:Drew EvansExplanation: Majestic on a truly cosmic scale, M100 is appropriately known as a grand design spiral galaxy. The large galaxy of over 100 billion stars haswell-defined spiral arms, similar to our own Milky Way. One of the brightest members of the Virgo Cluster of galaxies, M100,also known as NGC 4321 is 56 million light-years distant toward the well-groomed constellationComa Berenices. In this telescopic image, the face-on grand design spiral shares a nearly 1 degree wide field-of-view with slightly less conspicuousedge-on spiral NGC 4312 (at upper right).The 21 hour long equivalent exposure from a dark sky site nearFlagstaff, Arizona, planet Earth,reveals M100's bright blue star clusters and intricate winding dust lanes which are hallmarks of this class of galaxies. Measurements of variable stars in M100 have played an important role in determining the size and age of the Universe.

2024年05月01日:IC 1795：鱼头星云-（IC 1795: The Fishhead Nebula） 2024年05月01日:IC 1795：鱼头星云-（IC 1795: The Fishhead Nebula）--原图下载{mtitle title="IC 1795：鱼头星云"/}Image Credit & Copyright: Roberto Colombari & Mauro Narduzzi说明: 对某些人来说，这团星云形似鱼头。这幅彩色星空影像，呈现了位于北天仙后座内的恒星形成区IC 1795之辉光气体和不透光尘埃云。此星云的色彩则按照哈伯配色表，把源自氧、氢和硫原子的窄波段辐射依序渲染为蓝、绿和红等色泽；然后，这些数据再和透过宽波段滤镜拍摄的影像融合成这张照片。在天空中，IC 1795离着名的英仙双星团不远，本身则紧邻着IC 1805心脏星云，是一个大分子云边缘的恒星诞生区複合体之一部分。这个恒星诞生区複合体，蜿蜒分布在我们our 银河系的英仙旋臂上，离我们略远于6,000光年。依此距离，这幅影像涵盖了IC 1795约70光年宽的区域。{lamp/}原文：{mtitle title="IC 1795: The Fishhead Nebula"/}Image Credit & Copyright: Roberto Colombari & Mauro NarduzziExplanation: To some, this nebula looks like the head of a fish.However, this colorful cosmic portrait really featuresglowing gasand obscuring dust clouds in IC 1795,a star forming region in the northern constellation Cassiopeia.The nebula's colors were created by adopting theHubble color palettefor mapping narrowband emissions from oxygen, hydrogen,and sulfur atoms to blue, green and red colors, and furtherblending the data with images of the region recorded throughbroadband filters.Not far on the sky from the famous Double StarCluster in Perseus, IC 1795 is itself located next to IC 1805,the Heart Nebula, as part of acomplexof star forming regions that lieat the edge of a large molecular cloud.Located just over 6,000 light-years away, the largerstar forming complex sprawls along the Perseus spiral arm ofour Milky Way Galaxy.At that distance, IC 1795 would span about 70 light-yearsacross.

2024年04月30日:英仙GK：新星与行星状星云-（GK Per: Nova and Planetary Nebula） 2024年04月30日:英仙GK：新星与行星状星云-（GK Per: Nova and Planetary Nebula）--原图下载{mtitle title="英仙GK：新星与行星状星云"/}Image Credit & Copyright: Deep Sky Collective说明: 在这幅影像里，恒星系统英仙GK只和3个星云的其中之2有关联。在迄今已知的新星之中，距离1500光年远的英仙新星1901是第二近的新星。其中心藏着一颗白矮星，为一颗曾经的类太阳恒星残存的核心。环拱在英仙GK四周的圆形烟火星云，是在1901年看到的、发生在白矮星表面的一例热核爆炸（新星）所抛出的气体。烟火星云周围的红色发光气体，是曾披覆着此中心星的大气。这些形成弥漫行星状星云的气体，则在新星爆发前就已被释出。此外，飘过视野的暗淡灰色气体，应是恰好路过的星际卷云。在1901年，英仙GK发生新星爆发变得比参宿四还要明亮。在今年晚些时候，恒星系统北冕T预期也会发生新星爆发，不过具体的时间及亮度皆难以确定。{lamp/}原文：{mtitle title="GK Per: Nova and Planetary Nebula"/}Image Credit & Copyright: Deep Sky CollectiveExplanation: The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded.At the very center is a white dwarf star, the surviving core of a former Sun-like star.It is surrounded by the circular Firework nebula, gas that was ejected by a thermonuclear explosion on the white dwarf's surface -- a nova -- as recorded in 1901.The red glowing gas surrounding the Firework nebula is the atmosphere that used to surround the central star.This gas was expelled before the nova and appears as a diffuse planetary nebula. The faint gray gas running across is interstellar cirrus that seems to be just passing through coincidently.In 1901, GK Per's nova became brighter than Betelgeuse.Similarly, star system T CrB is expected to erupt in a nova later this year, but we don't know exactly when nor how bright it will become.

2024年04月29日:彗星、行星与月亮-（Comet, Planet, Moon） 2024年04月29日:彗星、行星与月亮-（Comet, Planet, Moon）--原图下载{mtitle title="彗星、行星与月亮"/}Image Credit &Copyright: Juan Carlos Casado(Starry Earth,TWAN)说明: 这个月前些天的日落后西方天空，同时出现3个明亮的天体，让资深的天文爱好者大饱眼福。其中最为人们所熟悉的，是带着蛾眉位相出现在上左方的月亮。而月亮的其余部分，受到了地球反射的阳光之照耀也隐约可见。左上角的明亮行星是木星，它同时也是太阳系最庞大的行星。三者中最不寻常的，是位于月亮下方的彗星12P/庞士-布鲁克斯，它右侧曳着粗短的尘尾，但却拥有向上方伸展、令人印象深刻的离子尾。这幅主题影像，组合自同一部相机摄于西班牙 赫罗纳省利尔斯村附近某地点的多张照片。庞士-布鲁克斯彗星在上星期通过了近日点，现在随着它移入南天并返回太阳系外围，其亮度也在下降之中。{lamp/}原文：{mtitle title="Comet, Planet, Moon"/}Image Credit &Copyright: Juan Carlos Casado(Starry Earth,TWAN)Explanation: Three bright objects satisfied seasoned stargazers of the western sky just after sunset earlier this month.The most familiar was the Moon, seen on the upper left in a crescent phase.The rest of the Moon was faintly visible by sunlight first reflected by the Earth.The bright planet Jupiter, the largest planet in the Solar System, is seen to the upper left. Most unusual was Comet 12P/Pons-Brooks, below the Moon and showing a stubby dust tail on the right but an impressive ion tail extending upwards. The featured image, a composite of several images taken consecutively at the same location and with the same camera, was taken near the village of Llers, in Spain's Girona province. Comet Pons-Brooks passed its closest to the Sun last week and is now dimming as it moves into southern skies and returns to the outer Solar System.

2024年04月28日:环状星云的外环-（Rings Around the Ring Nebula） 2024年04月28日:环状星云的外环-（Rings Around the Ring Nebula）--原图下载{mtitle title="环状星云的外环"/}Image Credit: Hubble, Large Binocular Telescope,Subaru Telescope; Composition & Copyright: Robert Gendler说明: 环状星云（M57）的结构，比小望远镜所见的要複杂。 轻易可见的是宽约1光年的中心环，不过如这幅整合3部大望远镜协同观测数据的极深空影像所示，在离这团星云中心星很远之处，还有许多会散发辉光的环状云气丝。这幅组合影像，结合了氢原子的红光辐射、可见光和红外光数据。环状星云是个外观偏长的的行星状星云，为类太阳恒星演化成白矮星时，所抛出的外层大气。环状星云位于天琴座方向约2,500光年远之处。{lamp/}原文：{mtitle title="Rings Around the Ring Nebula"/}Image Credit: Hubble, Large Binocular Telescope,Subaru Telescope; Composition & Copyright: Robert GendlerExplanation: The Ring Nebula (M57) is more complicated than it appears through a small telescope. The easily visible central ring is about one light-year across,but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes -exploresthe looping filaments of glowing gas extending much farther from the nebula's central star.This composite image includes red light emitted by hydrogen as well asvisible and infrared light.The Ring Nebula is an elongated planetary nebula, a type of nebula created when a Sun-like star evolves to throw off its outer atmosphere and become a white dwarf star. The Ring Nebula is about 2,500 light-years away toward the musicalconstellationLyra.

2024年04月27日:满天的月影-（All Sky Moon Shadow） 2024年04月27日:满天的月影-（All Sky Moon Shadow）--原图下载{mtitle title="满天的月影"/}Image Credit &Copyright:Tunc Tezel(TWAN)说明: 如果太阳在天空中，不过天空却是暗的，而四周的地平线反而很明亮，那么你可能是站在日全食期间的月影里。这幅组合全景影像所呈现的全天月影，係摄于地球 阿肯色州雪丽村附近的一座农场。而组合出这幅全天图的照片，则是在4月8日的日全食期间记录于清朗的天空下。从这个紧邻月影带中心线的地点看出去，日全食持续了4分多钟。在全食阶段，除了月亮剪影周围的日冕之外，还能看到行星和恒星。其中最容易辨认的，是位于全食日右下方及左上方的明亮金星和木星。{lamp/}原文：{mtitle title="All Sky Moon Shadow"/}Image Credit &Copyright:Tunc Tezel(TWAN)Explanation: If the Sun is upbut the sky is dark and the horizon is bright all around,you might be standing in the Moon's shadow during a total eclipse ofthe Sun.In fact, the all-sky Moon shadow shown in thiscomposited panoramic view was capturedfrom a farm near Shirley, Arkansas, planet Earth.The exposures were made under clear skies during theApril 8 total solar eclipse.For that location near the center line of the Moon's shadow track,totality lasted over 4 minutes.Along with the solar corona surrounding thesilhouette of the Moonplanets and stars were visible during the total eclipse phase.Easiest to see hereare bright planets Venus and Jupiter, to the lower rightand upper left of the eclipsed Sun.