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2021年09月08日:仙女大星系方向的深空影像-(The Deep Sky Toward Andromeda)
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欢迎来到人生天地间
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2017年11月29日:M42:猎户座大星云-(M42: The Great Orion Nebula)
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2017年08月06日:银河与炸裂的流星-(Milky Way and Exploding Meteor)
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2024年02月11日:直指月亮的火箭烟尘影子-(Rocket Plume Shadow Points to the Moon)
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2022-04-09
2022年04月09日:火星与土星的近合-(Mars-Saturn Conjunction)
2022年04月09日:火星与土星的近合-(Mars-Saturn Conjunction)--原图下载{mtitle title="火星与土星的近合"/}Image Credit &Copyright:Damian Peach说明: 在这片视野中,黄道星座.摩羯座里的较昏暗恒星散布在黄道面附近。不过,影像中心那二颗最亮的天体并不是恒星,而是火星与土星。这幅摄于4月4日清晨的望远镜影像,记录在黎明前的天空,这对行星以约1/3度(小于满月视张角)的间隔发生迷人的近合景象。你能分辨出那颗行星是那个吗?如果你猜火星是较红的那颗,你猜对了。位于火星上方稍暗一点的土星,在反射阳光后散发出淡黄的光芒。即便在低放大倍率下,仍可见到土星最大及最明亮的卫星土卫六,紧贴在土星的左侧。{lamp/}原文:{mtitle title="Mars-Saturn Conjunction"/}Image Credit &Copyright:Damian PeachExplanation: Fainter stars in the zodiacal constellation Capricornus arescattered near the plane ofthe eclipticin this field of view.The two brightest ones at center aren't stars at all though, butthe planets Mars and Saturn.Taken on the morning of April 4, thetelescopic snapshotcaptured their tantalizingclose conjunctionin a predawn sky, the pair of planets separatedby only about 1/3 of a degree.That's easily less than the apparent width of a Full Moon.Can you tell which planet is which?If you guessed Mars is the redder one , you'd be right.Above Mars, slightly fainter Saturn still shines with apaler yellowish tinge inreflected sunlight. Even at the low magnification, Saturn's largest and brightestmoon Titan can be spotted hugging the planet very closely on the left.
2022年04月09日
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2022-02-24
2022年02月24日:辇道增七-(Beautiful Albireo AB)
2022年02月24日:辇道增七-(Beautiful Albireo AB)--原图下载{mtitle title="辇道增七"/}Image Credit &Copyright: Robert Eder说明: 在人类的肉眼里,天鹅β(辇道增七)看起来是单颗亮星。距离约420光年远的这颗亮星,是标记着名天鹅座北十字星官底部的恒星。不过,如果透过小望远镜的目镜观看,它会分裂成为美丽的双星,一对水蓝与金黄的夜空珍宝。天鹅β的专名为Albireo,故常用Albireo AB来称呼这对双星的二颗明亮成员。在上图左侧的望远镜影像里,它们色泽上的差异即清楚可见,而右侧的嵌图则呈现它们星光的可见光谱。上方嵌图的光谱显示,辇道增七A是一颗温度比太阳低的K型星,最强烈的辐射出现在黄光与红光波段。其下的辇道增七B光谱显示,它是一颗远比太阳高温的主序星,在蓝光与紫外光波段发出最多辐射。辇道增七A本身是个双星系统,其成员星旋绕共同的质量中心运动,不过它们靠彼此太近,小望远镜并无法分解。而可清楚分解的辇道增七A与辇道增七B,在空间的各别运动明确有别,因此极可能只是光学双星,而非真正的物理双星系统。(Beta Cygni = Albireo 辇道增七、天鹅[座]β[星]){lamp/}原文:{mtitle title="Beautiful Albireo AB"/}Image Credit &Copyright: Robert EderExplanation: Beta Cygniis a single bright star to the naked eye.About 420 light-years awayit marks the foot of the Northern Cross, famous asterism inthe constellation Cygnus.But a view through the eyepiece of a small telescope will transform itinto a beautiful double star, atreasure of the night skyin blue and gold.Beta Cygni isalso known as Albireo,designated Albireo AB to indicate its two bright component stars.Their visually striking color difference is illustratedin this telescopic snapshot,along with their associatedvisible spectrumof starlight shown in insets to the right.Albireo A, top inset, shows the spectrum of a K-type giant star, cooler thanthe Sun and emitting most of its energy at yellow and red wavelengths.Below, Albireo B has the spectrum of a main sequence star much hotterthan the Sun, emitting more energy in blue and violet.Albireo Ais known to be a binary star, two stars together orbiting acommon center of mass, though the two stars are too close togetherto be seen separately with a small telescope.Well-separated Albireo A and B most likely representan optical double star and not a physical binary systembecausethe two components have clearly different measured motions through space.
2022年02月24日
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2022-02-19
2022年02月19日:特殊星系Arp 273-(Peculiar Galaxies of Arp 273)
2022年02月19日:特殊星系Arp 273-(Peculiar Galaxies of Arp 273)--原图下载{mtitle title="特殊星系Arp 273"/}Image Credit &Copyright: Jason Guenzel说明: 在这幅摄于住家后院的望远镜影像里,带芒的恒星近在我们银河系之内。而这两个很吸睛的星系,则座落在银河系后方3亿多光年远处。它们扭曲的外观,源自这对星系彼此接近时的重力潮汐效应。编录号为Arp 273 (亦称UGC 1810)的这对星系,外观诚然很特殊,但这种互扰星系,目前认为在宇宙其实很常见。例如:离我们约2百万光年远的仙女座大星系,就不停地往银河系靠,因此,Arp 273可能是未来互扰事件的告示牌。在长长的宇宙时间尺度期间,如果星系重覆接近,它们最后会合拼成单一星系。从地球看出去,星系对Arp 273的明亮星系核相隔约100,000光年。{lamp/}原文:{mtitle title="Peculiar Galaxies of Arp 273"/}Image Credit &Copyright: Jason GuenzelExplanation: The spiky starsin the foreground of this backyardtelescopic frame are well within our ownMilky Way Galaxy.But the two eye-catching galaxies lie far beyond the Milky Way,at a distance of over 300 million light-years.Their distorted appearance is due to gravitational tidesas the pair engage in close encounters.Cataloged as Arp 273 (also asUGC 1810), the galaxies do lookpeculiar,but interacting galaxies are now understood to becommon in the universe.Nearby, the large spiral Andromeda Galaxy is known to besome 2 million light-years away and approaching the Milky Way.The peculiar galaxies of Arp 273 may offer an analog of theirfar future encounter.Repeated galaxy encounters on acosmic timescale can ultimatelyresult in a merger into a single galaxy of stars.From our perspective, the bright cores of the Arp 273 galaxies areseparated by only a little over 100,000 light-years.
2022年02月19日
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2022-02-18
2022年02月18日:船尾座的三个星团-(Three Clusters in Puppis)
2022年02月18日:船尾座的三个星团-(Three Clusters in Puppis)--原图下载{mtitle title="船尾座的三个星团"/}Image Credit &Copyright: Dave Doctor说明: 银河星团(又称疏散星团)很年轻。不过,这些同时诞生于银河系盘面附近的成团恒星,在银河潮汐和彼此重力的交互作用之下,偶而会被弹飞出去,也因此星团成员的数量会不断减少。这幅超过3度宽的望远镜影像,就记录了南天.航海星座─船尾座方向的3个很典型之银河星团。它们分别是影像左下角约5,500光年远的M46,中右方近在1,600光年之处的M47,以及中上方约2,500光年远的NGC 2423。在约3亿年稚龄的M46里,它的数百颗成员星挤在宽约30光年的空间之内。目光犀利的读者,可在M46内的11点钟方向,看到编录号为NGC 2438的行星状星云。不过这团星云的中心星之年龄高达数十亿年,也因此,NGC 2438可能只是一个恰好出现在年轻M46视线方向的前景天体。而远更年轻、稚龄约8千万年的M47,是一个宽约10光年,相对较小也较鬆散的星团。在年龄约有7亿5千万年的星团NGC 2423里,天文学家找到一颗正在绕行星团内诸多红巨星之一的系外行星。{lamp/}原文:{mtitle title="Three Clusters in Puppis"/}Image Credit &Copyright: Dave DoctorExplanation: Galactic oropen star clustersare young.The swarms of stars are born together near the plane of the Milky Way,but their numberssteadily dwindleas cluster members areejected by galactic tides and gravitational interactions.Caught inthis telescopic frameover three degrees across are threegood examples of galactic star clusters,seen toward the southern sky's nautical constellationPuppis.Below and left, M46 issome 5,500 light-years in the distance.Right of centerM47 isonly 1,600 light-years away andNGC 2423 (top) is about 2500 light-years distant.Around 300 million years young M46contains a few hundred stars in a region about 30 light-yearsacross.Sharp eyes can spot a planetary nebula,NGC 2438,at about 11 o'clock against the M46 cluster stars.But that nebula'scentral staris billions of years old, andNGC 2438 is likely a foreground object only by chancealong the line of sight to youthful M46.Even younger, aged around 80 million years, M47 is asmaller and looser star cluster spanning about 10 light-years.Star cluster NGC 2423 is pushing about 750 million yearsin age though.NGC 2423 is known to harbor an extrasolar planet,detected orbiting oneof its red giant stars.
2022年02月18日
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2022-01-20
2022年01月20日:仙王座的NGC 7822-(NGC 7822 in Cepheus)
2022年01月20日:仙王座的NGC 7822-(NGC 7822 in Cepheus)--原图下载{mtitle title="仙王座的NGC 7822"/}Image Credit &Copyright:Mark Carter说明: 炽热的年轻恒星和气体及尘埃柱,看似全都挤到NGC 7822之内。这个在散发明亮辉光的恒星形成区,位在北天仙王座的一团庞大分子云之边缘,离我们约有3,000光年远。而这幅彩色的望远镜影像,则突显了星云内明亮的云气脊和绵延的尘埃柱。在这张整合窄波段滤镜数据的影像里,来自原子氧、氢和硫的辐射,分别上色为蓝、绿与红色。这些辐射线及其色泽对应组合,造就了名闻遐迩的哈伯色表。这些原子辐射是受到炽热中心恒星的高能辐射之驱动,此外,恒星的强烈的恒星风和星光,也雕塑和侵蚀较緻密的尘埃柱,并在诞生它们的云气里,清出了一个宽达数光年的特徵性空穴。云柱之内,仍持续经由重力塌缩过程形成恒星之中,不过随着云柱侵蚀殆尽,任何还在形成中的恒星,都会失去造星物质的储存库。以NGC 7822的距离来推算,这张影像约莫涵盖40光年宽的区域。{lamp/}原文:{mtitle title="NGC 7822 in Cepheus"/}Image Credit &Copyright:Mark CarterExplanation: Hot, young stars andcosmic pillarsof gas and dust seem to crowd into NGC 7822.At the edge of a giantmolecular cloud toward the northernconstellation Cepheus, the glowing star forming regionlies about 3,000 light-years away.Within the nebula, bright edges and dark shapes stand out in thiscolorfultelescopic skyscape.The image includes data from narrowband filters,mapping emission from atomic oxygen, hydrogen, and sulfur into blue,green, and red hues.The emission line and color combination has become well-known as theHubble palette. The atomic emission ispowered by energetic radiation fromthe central hot stars.Their powerful winds and radiation sculpt and erodethe denser pillar shapes and clear out acharacteristic cavity light-years acrossthe center of the natal cloud.Stars could still be forming inside the pillars bygravitational collapse but as the pillars areeroded away, any forming stars will ultimately be cutoff from theirreservoir ofstar stuff.This field of view spans about 40 light-years at the estimated distanceof NGC 7822.
2022年01月20日
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2021-12-24
2021年12月24日:M1:蟹状星云-(M1: The Crab Nebula)
2021年12月24日:M1:蟹状星云-(M1: The Crab Nebula)--原图下载{mtitle title="M1:蟹状星云"/}Image Credit &Copyright:Michael Sherick说明: 编号为M1的蟹状星云,是梅西叶在18世纪编录的着名“非彗星”星表里的第一号天体。 如今的我们当然知道蟹状星云是个超新星遗迹,为大质量恒星死亡爆炸所留下来的碎片云,而(北宋的)天文学家于西元1054年有第一手的观测记录。这幅清晰的地面望远镜影像,整合了源自电离硫、氢、和氧原子的窄和宽波段彩色辐射 资讯,以探索这团仍然不停the still 扩张的星云内之纠结云气丝。身为现代天文学家所知最奇特的天体之一的蟹状星云波霎,是影像中心附近的亮斑,为一颗每秒自转30次的中子星。这个恒星核心的崩塌孑遗,行为像一部宇宙级的发电机,驱动蟹状星云发出横跨所有电磁波段的辐射。跨幅约有12光年的蟹状星云,位在金牛座方向6,500光年远之处。{lamp/}原文:{mtitle title="M1: The Crab Nebula"/}Image Credit &Copyright:Michael SherickExplanation: The Crab Nebula is cataloged as M1, the first object onCharles Messier'sfamous 18th century list of things which are not comets.In fact,the Crabis now known to be asupernova remnant,debris from the death explosion of a massive star,witnessedby astronomers in the year 1054.This sharp, ground-basedtelescopic view combines broadband color data withnarrowband data that tracks emission from ionized sulfur, hydrogen, andoxygen atoms to explore the tangled filaments withinthe still expanding cloud.One of the most exotic objects known to modern astronomers,the Crab Pulsar,a neutron star spinning 30 times a second,is visible as a bright spot nearthe nebula's center.Like a cosmic dynamo,this collapsed remnant of the stellar corepowers the Crab's emission across the electromagnetic spectrum.Spanning about 12 light-years, the Crab Nebula is a mere6,500 light-years away in theconstellation Taurus.
2021年12月24日
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