2024年01月16日:肉眼几乎可见的猎户座-（The Orion You Can Almost See） [2024年01月16日:肉眼几乎可见的猎户座-（The Orion You Can Almost See）--原图下载](https://apod.nasa.gov/apod/image/2401/OrionMcc_Guzzini_1366.jpg"onMouseOver="if (document.images)document.imagename1.src='image/2401/OrionMcc_Guzzini_960_annotated.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/2401/OrionMcc_Guzzini_960.jpg';){mtitle title="肉眼几乎可见的猎户座"/}Image Credit & Copyright: Michele Guzzini说明: 你认得这个星座吗？儘管它是天空中最容易辨认的星群之一，但这种与肉眼所见比较更加完整的猎户座，只有透过长曝光数位相机成像及电脑后製处理才得以显现。在此影像里，带着深橙色调的低温红巨星参宿四，是位于左上角的最明亮恒星。猎户座的炽热泛蓝恒星数量众多，其中，右下角的超巨星参宿七，亮度足以和左上角的参宿四相抗衡，而右上角的亮星则是参宿五。距离我们全约为1,500光年远的猎户腰带三星，皆诞生于猎户座备受研究的星际云里。猎户腰带下方有一片明亮但模糊的光斑，它看来或许也有点眼熟，这是因为它是名为猎户大星云的恒星孕育室。最后是肉眼勉强可见但相当引人注目的巴纳德环，这团环拱在猎户腰带和猎户大星云周围的庞大发射星云，是由猎户座摄影先锋巴纳德发现于100多年前。（Betelgeuse 参宿四; Rigel 参宿七; Bellatrix 参宿五; Barnard's Loop 巴纳德环; Hatysa 伐三; Alnitak 参宿一; Alnilam 参宿二; Mintaka 参宿三; Saiph 参宿六; Cursa 玉井三-波江座）{lamp/}原文：{mtitle title="The Orion You Can Almost See"/}Image Credit & Copyright: Michele GuzziniExplanation: Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, this is a more full Orion than you can see -- an Orion only revealed with long exposure digital camera imaging and post-processing. Here the cool red giant Betelgeuse takes on a strong orange tint as the brightest star on the upper left. Orion's hot blue stars are numerous, with supergiant Rigel balancing Betelgeuse on the lower right, and Bellatrix at the upper right.Lined up in Orion's belt are three stars all about 1,500 light-years away, born from the constellation's well-studied interstellar clouds.Just below Orion's belt is a bright but fuzzy patch that might also look familiar -- the stellar nursery known as Orion's Nebula. Finally, just barely visible to the unaided eye but quite striking here is Barnard's Loop -- a huge gaseous emission nebula surrounding Orion's Belt and Nebula discovered over 100 years ago by the pioneering Orion photographer E. E. Barnard.

2023年12月26日:IC 443：水母星云-（IC 443: The Jellyfish Nebula） 2023年12月26日:IC 443：水母星云-（IC 443: The Jellyfish Nebula）--原图下载{mtitle title="IC 443：水母星云"/}Image Credit & Copyright: David Payne说明: 为何会有水母悠游在恒星海里？影像中漂浮在亮星銊（右侧）附近的水母星云，其触手往中左方的弧形亮脊方向伸展。水母星云其实是气泡状超新星遗迹IC 443的一部份，是一颗大质量恒星爆炸后所留下的扩张碎片云。来自这个超新星爆炸的亮闪，大约在30,000年前首次传到地球。就像它在天文海洋里的同类--超新星遗迹蟹状星云一样，IC 443之内也藏着一颗星核崩塌后形成的中子星。水母星云离我们约5,000光年远。以此距离来换算，这张主题影像的跨幅约为140光年。（Jellyfish Nebula 水母星云; Eta Gem 銊）{lamp/}原文：{mtitle title="IC 443: The Jellyfish Nebula"/}Image Credit & Copyright: David PayneExplanation: Why is this jellyfish swimming in a sea of stars?Drifting near bright star Eta Geminorum, seen at the right, the Jellyfish Nebula extends its tentacles from the bright arcing ridge of emission left of center. In fact, the cosmic jellyfish is part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded. Light from the explosion first reached planet Earth over 30,000 years ago. Like its cousin in astronomical waters, the Crab Nebula supernova remnant IC 443 is known to harbor a neutron star -- the remnant of the collapsed stellar core. The Jellyfish Nebula is about 5,000 light-years away. At that distance, the featured image would span about 140 light-years across.

2023年10月30日:鬼魂星魂-（Reflections of the Ghost Nebula） 2023年10月30日:鬼魂星魂-（Reflections of the Ghost Nebula）--原图下载{mtitle title="鬼魂星魂"/}Image Credit & Copyright: Bogdan Jarzyna说明: 在这片恒星和尘埃里，有没有天体马上抓住你的目光？这些广袤、宝石般、内有不停反射暗淡星光云气的星云，漂流在仙王座方向的夜空中。 这些座落在地球外头约1,200光年远处的星云，位于银河盘面的仙王火焰分子云複合体的边缘。在这张主题影像底部，长超过2光年，比其他幽灵状云气要明亮的的怪物般云气，则是VdB 141（亦称Sh2-136、鬼魂星云或幽云星云）。 在这团反射星云里的緻密云核，已展现出处在恒星形成阶段的早期、正在发生塌缩的诸多特徵迹证。{lamp/}原文：{mtitle title="Reflections of the Ghost Nebula"/}Image Credit & Copyright: Bogdan JarzynaExplanation: Do any shapes seem to jump out at you from this interstellar field of stars and dust? The jeweled expanse, filled with faint, starlight-reflectingclouds, drifts through the night in the royal constellation of Cepheus.Far from your own neighborhood on planet Earth, these ghostly apparitions lurk along theplane of the Milky Way at theedge of the Cepheus Flaremolecular cloud complex some 1,200 light-years away.Over two light-years across and brighter than the other spooky chimeras, VdB 141 or Sh2-136 is also known as theGhost Nebula, seen toward the bottom of the featured image.Within the reflection nebula are the telltale signs of dense corescollapsingin the earlystages of star formation.

2023年10月07日:仙女大星系过去和未来的恆星-（The Once and Future Stars of Andromeda） [2023年10月07日:仙女大星系过去和未来的恆星-（The Once and Future Stars of Andromeda）--原图下载](https://apod.nasa.gov/apod/image/2310/M31_HubbleSpitzerGendler_2000.jpg"onMouseOver="if (document.images)document.imagename1.src='image/2310/M31_HubbleSubaruGendler_960.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/2310/M31_HubbleSpitzerGendler_960.jpg';){mtitle title="仙女大星系过去和未来的恆星"/}Image Credit: NASA, NSF, NOAJ, Hubble, Subaru,Mayall, DSS, Spitzer; Processing & Copyright: Robert Gendler & Russell Croman说明: 这幅仙女大星系的影像，不仅显示目前恒星之所在，也呈现了未来恒星即将现身的位区。如众所熟知的，庞大美丽的仙女大星系（M31），是个离我们只有2百50万光年远的螺旋星系。这幅很有趣的仙女大星系组合影像，整合了太空与地基望远镜的观测数据，以同时呈现此星系在可见光及非可见光波段的景观。影像里的白与蓝色、呈现哈伯、昴宿、及Mayall望远镜的可见光数据，用以突显M31目前恒星所在的位置。而来自美国航太总署．史匹哲太空望远镜的橙色红外光数据，则显示M31未来的恒星即将形成的区域。红外光数据所显示的，是仙女大星系广袤的螺旋臂上，受到恒星加热的庞然尘埃带。这些尘埃是此星系大量星际气体的示踪物，更是未来恒星形成的原材料。很可确定的是，这些新恒星很可能会形成于接下来的一亿年里，远在约50亿年后仙女座与我们的银河系合併之前。{lamp/}原文：{mtitle title="The Once and Future Stars of Andromeda"/}Image Credit: NASA, NSF, NOAJ, Hubble, Subaru,Mayall, DSS, Spitzer; Processing & Copyright: Robert Gendler & Russell CromanExplanation: This picture of Andromeda shows not only where stars are now, but where stars will be.The big, beautiful Andromeda Galaxy,M31, is a spiral galaxya mere 2.5 million light-yearsaway. Image data from space-based and ground-based observatories have been combined here to produce this intriguing compositeview of Andromeda at wavelengths bothinside and outside normally visible light.The visible lightshows where M31's stars are now, highlighted inwhite and blue hues and imaged by the Hubble, Subaru, and Mayall telescopes. The infrared lightshows where M31's future stars will soon form,highlighted in orange hues and imaged by NASA's Spitzer Space Telescope. The infrared light tracks enormous lanes of dust, warmed by stars, sweeping along Andromeda's spiral arms. This dust is a tracer of the galaxy's vastinterstellar gas, raw material for future star formation. Of course, the new stars will likely form over the next hundred million years or so.That's well before Andromeda merges with our Milky Way Galaxy in about 5 billion years.

2023年09月04日:天鹅座的皂泡与眉月星云-（Cygnus: Bubble and Crescent） 2023年09月04日:天鹅座的皂泡与眉月星云-（Cygnus: Bubble and Crescent）--原图下载{mtitle title="天鹅座的皂泡与眉月星云"/}Credit & Copyright: Abdullah Al-Harbi说明: 恒星濒死时会创造星云。这二团恒星死亡时所产生的气体与尘埃云，漂流在银河系盘面天鹅座方向的富星场里。位在这幅望远镜视野里的皂泡星云（左下）及眉月星云（右上），都是由处在最终演化阶段的恒星所产生的。其中，亦名为NGC 6888的眉月星云，是由位在其中心的明亮大质量沃夫-瑞叶恒星（WR 136），以强烈的恒星风抛出它的外层气壳所形成的。而以惊人速率消耗核燃料的WR 136，处在它短暂生命的终点附近，最后会以壮观的超新星爆炸谢幕。2013年才发现的皂泡星云，很可能是个行星状星云；它是一颗注定将成为缓缓冷却白矮星的长寿、小质量类太阳恒星所抛出之气体寿衣。这二团星云的距离都在5,000光年上下，较庞大的眉月星云跨幅约为25光年。在数百万年之内，这二团星云可能都会消散匿蹤。{lamp/}原文：{mtitle title="Cygnus: Bubble and Crescent"/}Credit & Copyright: Abdullah Al-HarbiExplanation: As stars die, they create clouds. Two stellar death clouds of gas and dust can be found toward the high-flying constellation of the Swan (Cygnus)as they drift throughrich star fields in the plane of our Milky Way Galaxy.Caught here within thetelescopicfield of view are theSoap Bubble (lower left) and theCrescent Nebula (upper right).Both were formed at the final phase in the life of a star.Also known as NGC 6888,the Crescent Nebula was shaped as its bright, central massiveWolf-Rayetstar, WR 136, shed its outer envelope ina strong stellar wind.Burning through fuel at a prodigious rate, WR 136 is near the end ofa short lifethat should finish in a spectacularsupernova explosion.Discovered in 2013, the Soap Bubble Nebula is likely aplanetarynebula, the final shroud of a lower mass, long-lived, Sun-like stardestined to become a slowly cooling white dwarf.Both stellar nebulas are about 5,000 light-years distant, with the larger Crescent Nebula spanning about 25 light-years across.Within a few million years, both will likely have dispersed.

2023年04月08日:M100：宏伟的螺旋星系-（M100: A Grand Design Spiral Galaxy） 2023年04月08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: NASA, ESA, Hubble;Processing: Judy Schmidt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，位在后发座方向，离我们约有5千6百万光年远，是室女座星系团最明亮的星系成员之一。这幅由哈伯太空望远镜第三代广视场相机所拍摄的M100影像，突显了明亮蓝色星团和错综複杂的蜿蜒尘埃带，这些螺旋星系的标誌性特徵。研究星系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: NASA, ESA, Hubble;Processing: Judy SchmidtExplanation: Majestic on a truly cosmic scale, M100 is appropriately known as a grand design spiral galaxy. It is a large galaxy of over 100 billion stars with well-defined spiral arms that is similar to our own Milky Way Galaxy. One of the brightest members of the Virgo Cluster of galaxies, M100 (alias NGC 4321) is 56 million light-years distant toward the constellation of Berenice's Hair (Coma Berenices). This Hubble Space Telescope image of M100 was taken with the Wide Field Camera 3 and accentuates bright blue star clusters and intricate winding dust lanes which are hallmarks of this class of galaxies. Studies of variable stars in M100 have played an important role in determining the size and age of the Universe.