首页
关于人生天地间
Search
1
2021年09月08日:仙女大星系方向的深空影像-(The Deep Sky Toward Andromeda)
36 阅读
2
2017年11月29日:M42:猎户座大星云-(M42: The Great Orion Nebula)
25 阅读
3
欢迎来到人生天地间
24 阅读
4
2017年08月06日:银河与炸裂的流星-(Milky Way and Exploding Meteor)
13 阅读
5
2024年02月11日:直指月亮的火箭烟尘影子-(Rocket Plume Shadow Points to the Moon)
9 阅读
默认分类
每日天文图
登录
Search
标签搜索
地球
太阳
尘埃
银河系
光年
dust
Sun
哈伯太空望远镜
影像
Hubble Space Telescope
火星
主题影像
Earth
Milky Way Galaxy
上图
木星
土星
美国
太阳系
人生天地间
累计撰写
10,534
篇文章
累计收到
1
条评论
首页
栏目
默认分类
每日天文图
页面
关于人生天地间
搜索到
10
篇与
的结果
2019-11-30
2019年11月30日:红色行星的星像迹线-(Star Trails for a Red Planet)
2019年11月30日:红色行星的星像迹线-(Star Trails for a Red Planet)--原图下载{mtitle title="红色行星的星像迹线"/}Image Credit &Copyright: Dengyi Huang说明: 火星有极星吗?在地球夜空的长曝光影像里,恒星以地球自转轴所指的北天极为中心,曳出一道道同心的圆弧。在目前,北极星是离地球北天极最近的亮星。在摄于火星的长曝光影像里,恒星也会因火星自转而曳出绕天极的迹线。虽然火星自转轴的倾角和地球相近,不过它在空间的指向和地轴不同。它目前指向天鹅座和仙王座之间的恒星,不过该区并没像地球北极星这种亮星。所以虽然这幅影像里的暗红风化地貌,酷似火星表面的原野,但实际上是摄于地球。在影像里,北极星位在同心星像迹线的中心。而前景的地貌,则位在中国西北部的青海省。{lamp/}原文:{mtitle title="Star Trails for a Red Planet"/}Image Credit &Copyright: Dengyi HuangExplanation: DoesMars have a north star?In long exposures ofEarth's night sky,star trails make concentric arcsaround the north celestial pole, the direction of ourfair planet's axis of rotation.Bright star Polarisis presently the Earth's North Star, close on the sky toEarth's north celestial pole.But long exposures onMarsshow star trails too,concentric arcs about a celestial pole determined by Mars' axis ofrotation.Tilted like planet Earth's, the martian axis of rotation pointsin a different direction in space though.Itpoints to a place on the sky between stars in Cygnus and Cepheuswith no bright star comparable to Earth's north star Polaris nearby.So even though this ruddy, weathered landscape isremarkablyreminiscent of terrain in images from themartian surface, the view must be from planet Earth,with north star Polaris near the center of concentric star trails.The landforms in the foreground are found inQinghai Province innorthwestern China.
2019年11月30日
0 阅读
0 评论
0 点赞
2018-11-08
2018年11月08日:火星逆行-(Mars in the Loop)
[2018年11月08日:火星逆行-(Mars in the Loop)--原图下载](https://apod.nasa.gov/apod/image/1811/Ma2018_tezelN.jpg"onMouseOver="if (document.images)document.imagename1.src='image/1811/Ma2018La_tezelN1024.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/1811/Ma2018_tezelN1024.jpg';){mtitle title="火星逆行"/}Image Credit &Copyright: Tunc Tezel(TWAN)说明: 这张组合影像取像的间隔介于5到9天之间,横跨4月底(右下)到10月底(左上)期间,以追蹤泛红火星在地球夜空中的逆行运动。如果想串连这张2018年火星逆行迴圈影像的像点以及发生的日期,只要把鼠标移到影像之上,而在此同时,也别错过这部动画。当然火星并不会真的在轨道上倒着走,它在视觉上相对于背景恒星的逆行,其实只是反应了地球本身的运动。由于地球比外围行星靠近太阳,在轨道上移动较快速,所以每次只要地球追过外围行星,就能见到行星逆行的景观。2018年观测火星的最佳时间点是7月27日,当时在“近日点冲”附近的火星,位在轨道上最近太阳的位置,同时在地球天空中与太阳反向。用来组成这张影像的背景图,就是摄于那一天月全食发生的期间。{lamp/}原文:{mtitle title="Mars in the Loop"/}Image Credit &Copyright: Tunc Tezel(TWAN)Explanation: This composite of images spaced some 5 to 9 days apart,from late April (bottom right) through November 5 (top left),traces the retrograde motion ofruddy-colored Mars throughplanet Earth's night sky.To connect the dots and dates in this 2018 Mars retrograde loop,just slide your cursor over the picture(and check out this animation).But Mars didn't actually reverse the direction of its orbit.Instead, the apparent backwards motion with respect to the backgroundstars is a reflection of the motion of the Earth itself.Retrograde motioncan beseen each time Earth overtakesand laps planets orbiting farther from the Sun, theEarth moving more rapidly through its own relatively close-in orbit. On July 27, Mars was near its favorable 2018 perihelic opposition,when Mars was closest to the Sun in its orbitwhile alsoopposite the Sun in Earth's sky.For that date, the frame used in this composite was taken during thetotal lunar eclipse.
2018年11月08日
0 阅读
0 评论
0 点赞
2018-03-25
2018年03月25日:船底座新星2018 -(Announcing Nova Carinae 2018)
2018年03月25日:船底座新星2018 -(Announcing Nova Carinae 2018)--原图下载{mtitle title="船底座新星2018 "/}Image Credit & Copyright: A. Maury & J. Fabrega说明: 船底座新星2018未来会变多亮呢?这颗新星上星期才刚发现。虽然新星经常出现在宇宙各处,但在影像中以箭头标示,出现在美丽的船底座大星云附近,编录号为ASASSN-18fv的这颗新星,在地球夜空中异常的明亮,用双筒望远镜就能在南半球的天空见到它。新星的成因,通常是白矮星表面累积了来自伴星的物质,因而发生热核爆炸,但这类爆发的细节目前仍不明。在接下来的数星期之中,职业和业余天文学家都会持续监控这个不寻常的恒星爆发,看船底座新星2018会如何演化,包括它是否会增亮到肉眼可见的程度。(Nova Carinae 2018 船底座新星2018){lamp/}原文:{mtitle title="Announcing Nova Carinae 2018"/}Image Credit & Copyright: A. Maury & J. FabregaExplanation: How bright will Nova Carinae 2018 become?The new nova was discovered only last week.Although novas occur frequently throughout the universe, this nova, cataloged as ASASSN-18fv, is so unusually bright in the skies of Earth that it is now easily visible through binoculars in the southern hemisphere.Identified by the arrow, the nova occurs near the direction of the picturesque Carina Nebula.A nova is typically caused by a thermonuclear explosion on the surface of a white dwarf star that is accreting matter from a binary companion, although details of this outburst are currently unknown. Both professional and amateur astronomers will be monitoring this unusual stellar outburst in the coming weeks, looking to see how Nova Carinae 2018 evolves, including whether it becomes bright enough to be visible to the unaided eye.
2018年03月25日
0 阅读
0 评论
0 点赞
2018-03-16
2018年03月16日:海鸥与鸭子-(The Seagull and the Duck)
2018年03月16日:海鸥与鸭子-(The Seagull and the Duck)--原图下载{mtitle title="海鸥与鸭子"/}Image Credit &Copyright: RaulVillaverde Fraile说明: 这二团看似海鸥与鸭子的星云,并非是唯二会让我们联想到飞行的宇宙云。不过,在这片涵盖地球夜空的大犬座天区、接近7度的辽阔宇宙视野里,它们正在展翅高飞。宽广的海鸥星云(中上方),是由二个各拥有编录号的大型发射星云所组成。较明亮的NGC 2327构成头部,较弥漫的IC 2177则是翅膀和身躯。以这团星云3,800光年的估计距离来换算,这只海鸥有令人叹为观止的250光年宽翼展。位在影像右下角的鸭子星云较紧实,以它大约15,000光年的距离来估算,跨幅大约只有50光年。编录号为NGC 2359的鸭子星云,是由位在它中心的极大质量炽热恒星之高能恒星风吹袭而成。除此之外,这只鸭子厚实的身躯和侧翼,也为它博得"雷神的头盔"这个较生动且常见的别名。{lamp/}原文:{mtitle title="The Seagull and the Duck"/}Image Credit &Copyright: RaulVillaverde FraileExplanation: Seen as a seagull and a duck, these nebulae arenot the onlycosmic clouds toevoke images of flight.But both are winging their way across this broadcelestial landscape, spanning almost 7 degrees acrossplanet Earth's night skytoward the constellationCanis Major.The expansive Seagull(top center)isitself composed oftwo major catalogedemission nebulae.Brighter NGC 2327 forms the head with the more diffuseIC 2177 as the wings and body.Impressively, the Seagull'swingspan would correspond to about 250 light-years atthe nebula's estimated distance of 3,800 light-years.At the lower right, the Duck appears much more compact andwould span only about 50 light-years given its15,000 light-year distance estimate.Blown by energetic winds from an extremely massive,hot star near its center, the Duck nebula is catalogedas NGC 2359.Of course, the Duck's thick body and winged appendagesalso lend it the slightly more dramatic popular moniker,Thor's Helmet.
2018年03月16日
0 阅读
0 评论
0 点赞
2013-07-20
2013年07月20日:Lemmon彗星与其他深空天体-(Comet Lemmon and the Deep Sky)
2013年07月20日:Lemmon彗星与其他深空天体-(Comet Lemmon and the Deep Sky)--原图下载{mtitle title="Lemmon彗星与其他深空天体"/}Image Credit &Copyright: Nick Martin说明: 高掠在银河盘面上方的Lemmon彗星 (Comet Lemmon;Lemmon读音如「莲檬」),随着它往太阳外围行进,在地球夜空中的亮度已急遽下降。然而,在上星期拍摄的这幅4度视野望远镜影像里,除了可看见仙后座的星团之外,也见到这颗大约离太阳二光分 (2天文单位)的彗星,仍拥有绿色的彗发。实际上,位在恒星密集银河盘面的这个北天星座里,见到如上图这种富星场是常态。影像中央有5,000光年远的疏散星团M52;其左下方有带着红色辉光的星云NGC 7635,这个11,000光年远的星云,在特写影像中,因它的外观而被称为是泡泡星云 (the Bubble Nebula)。逐渐暗去的Lemmon彗星,可不是影像中唯一的前景天体,一艘地球轨道卫星正好在影像曝光期间穿过视野,它进入地球夜面时,仍沐浴在阳光的闪烁身影,造成了影像中的黯淡光迹。{lamp/}原文:{mtitle title="Comet Lemmon and the Deep Sky"/}Image Credit &Copyright: Nick MartinExplanation: Now sweepinghigh above the ecliptic plane,Comet Lemmonhas faded dramatically inplanet Earth's night skyas it heads for the outer solar system.Some 16 light-minutes (2 AU) from the Sun, it still sports agreenish coma though, posing on the rightin this 4 degree widetelescopic view fromlast Saturday with deep sky star clusters and nebulaein Cassiopeia.In fact, the rich background skyscape istypical within the boundaries of theboastful northernconstellation that lie along the crowded starfields of the Milky Way.Included near center is openstar cluster M52about 5,000 light-years away.Around 11,000 light-years distant, the red glowing nebula NGC 7635below and left of M52 is well-known for its appearance in close-upimages as the Bubble Nebula.But the fading Comet Lemmon is not the only foreground object onthe scene.A faint streak on the right is an orbiting satellitecaught crossing through the field during the long exposure, glintingin the sunlight and winking out as itpasses into Earth's shadow.
2013年07月20日
0 阅读
0 评论
0 点赞
2012-08-09
2012年08月09日:火星逆行-(Mars in the Loop)
[2012年08月09日:火星逆行-(Mars in the Loop)--原图下载](https://apod.nasa.gov/apod/image/1208/Ma2011-2Tezel.jpg"onMouseOver="if (document.images)document.imagename1.src='image/1208/Ma2011-2Tezel_La900.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/1208/Ma2011-2Tezel900.jpg';){mtitle title="火星逆行"/}Image Credit &Copyright: Cenk E. Tezel,Tunç Tezel(TWAN)说明: 这幅组合了间隔5或7天数据的影像,呈现了2011年10底至2012年6月初之间,红色火星在地球夜空的逆行运动。把滑鼠移到上方影像,就能带出另一幅加上连点线和日期注记的影像。事实上,火星不是真得发生"逆行",它相对于背景恒星的视运动,只是地球本身的运动所造成的效应。由于地球在较靠太阳的内侧轨道运行,速度较外侧的行星快,因此每次超越外行星都会发生逆行的现象。2012年3月4日火星冲 (opposite)发生时,因最近地球而显得很明亮的火星位在影像之中心。刚降落在火星表面的好奇号探测车,发射于2011年11月26日,当时火星位在迴圈的交叉点附近。这段期间日落后的西方天空,火星出现在土星和亮星角宿一 (Spica)附近。{lamp/}原文:{mtitle title="Mars in the Loop"/}Image Credit &Copyright: Cenk E. Tezel,Tunç Tezel(TWAN)Explanation: This composite of images spaced some 5 to 7 days apartfrom late October 2011 (top right) through early July 2012(bottom left), traces theretrograde motion of ruddy-colored Mars throughplanet Earth's night sky.To connect the dots in Mars' retrograde loop,just slide your cursor over the picture(and check outthisanimation).But Mars didn't actually reverse the direction of its orbit.Instead, the apparent backwards motion withrespect to the background stars is areflection of the motion of the Earth itself.Retrograde motioncan beseen each time Earth overtakesand laps planets orbiting farther from the Sun, theEarth moving more rapidly through its own relatively close-in orbit. On March 4th, 2012 Mars was opposite the Sun inEarth's sky, near its closest and brightest at the center of this picture.Just arrivedon thesurface of the Red Planet, theCuriosity rover was launched on November 26, when Mars wasnear the crossover point of its retrograde loop.Of course, Mars can now be spottedclose to Saturn and bright star Spica, nearthe westernhorizon after sunset.
2012年08月09日
0 阅读
0 评论
0 点赞
1
2