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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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2000-01-17
2000年01月17日:V4641 Sgr: 最靠近我们的黑洞候选天体-(V4641 Sgr: The Closest Black Hole Candidate)
2000年01月17日:V4641 Sgr: 最靠近我们的黑洞候选天体-(V4641 Sgr: The Closest Black Hole Candidate)--原图下载{mtitle title="V4641 Sgr: 最靠近我们的黑洞候选天体"/}Credit: Robert M. Hjellming et al., VLA,NRAO说明: 不久之前,天文学家找到一个可能是黑洞的天体 - V4641 ,它的距离只有1500光年,所以它可能是最靠近我们的黑洞。上图拍摄在V4641刚发生一次无线电波段的爆发后,虽然这个天体不停地发生爆炸,但很幸运地它离得够远,所以我们并没有任何危险。在照片中,我们可能看见从V4641射出的喷流,这类喷流延续的时间通常在数分钟左右。 V4641是天文学家找到的第四个 微型类星体 (microquasar),它很像星系核心会喷出强大物质流的黑洞,只不过规模小得多而已。 因为并没有物质或讯号能从黑洞逃出来,所以,这些爆炸并不是源自黑洞的内部,而是发生在它的周围。喷流的形成是物质迴旋掉入黑洞时,愈靠中心物质愈密集,因为摩擦而产生高热,造成部份物质喷出。就是以黑洞的标准来说,V4641的行为也是非常怪异。天文学家正试着要去了解,为什么它的爆发只延续数分钟而已,而且每次爆发发生的波段多不一样。{lamp/}原文:{mtitle title="V4641 Sgr: The Closest Black Hole Candidate"/}Credit: Robert M. Hjellming et al., VLA,NRAOExplanation: An object many astronomers believe is a black hole has been found only 1500 light-years from Earth, making it the closest black hole candidate. Although dramatic explosions emanate from the object, it is far enough away so that we are in no danger. Pictured above, V4641 was imaged just after emitting an outburst in the radio band. Jets, which lasted only minutes, are visible. V4641 is the fourth known microquasar, a miniature version of the massive, matter spewing black holes thought to exist in the centers of galaxies. The explosions are not thought to emanate from within the black hole, a location where neither matter nor information can escape, but from around the black hole, where matter from its companion star may be heating up as it falls in. Astronomers are working to understand why V4641 acts strangely even for a black hole, as the explosions it creates fade within minutes, and appear at different times in different bands of light.
2000年01月17日
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1999-11-01
1999年11月01日:"臭蛋"行星状星云 (The Rotten Egg Planetary Nebula)-(The Rotten Egg Planetary Nebula)
1999年11月01日:"臭蛋"行星状星云 (The Rotten Egg Planetary Nebula)-(The Rotten Egg Planetary Nebula)--原图下载{mtitle title=""臭蛋"行星状星云 (The Rotten Egg Planetary Nebula)"/}Credit: W. B. Latter (Caltech) et al., ESA, NASA说明: 并不是所有恒星在演化过中所抛出的气壳,外观都和人很相似。OH231.8+4.2 是一颗和我们的太阳很相像的恒星,不过在它的核心,已经耗尽了核融合的燃料。 所以,它不得不演化到行星状星云 (planetary nebula)的阶段,抛出它外层的气壳,而残留下的星核心将会成一颗 白矮星。不过,这些和太阳相似的恒星,它们所产生的行星状星云,在外观上有很大的差别,而OH231.8+4.2所产生的星云,看起来很像是人。在这张最近发布的哈伯望远镜照片里,我们也可以看到从壮观的气体喷流。 这个星云因为含有不寻常高量的硫,所以又被称为 "臭蛋"行星状星云 ,因为硫的味道和发臭的蛋很像。 在数千年内,这个行星状星云的外观可能会有很大的变化,最后甚到会消散无蹤。{lamp/}原文:{mtitle title="The Rotten Egg Planetary Nebula"/}Credit: W. B. Latter (Caltech) et al., ESA, NASAExplanation: Not all evolving stars eject gas clouds that look like people. OH231.8+4.2 was a star much like our Sun that ran out of nuclear fuel to fuse in its core. It has therefore entered the planetary nebula phase, where it throws off its outer atmosphere into space leaving a core that will become a white dwarf star. Every Sun-like star creates a different planetary nebula though, and OH231.8+4.2's looks eerily like a person! Spectacular jets of streaming gas can be seen in this recently released photograph by the Hubble Space Telescope. The gas cloud has been dubbed the Rotten Egg Planetary Nebula because it contains unusually high amounts of sulfur, an element that, when combined with otherelements, can smell like a rotten egg. This young planetary nebula will likely change its appearance over the next few thousand years and eventually disperse.
1999年11月01日
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1999-09-29
1999年09月29日:X-射线波段的蟹状星云-(The Crab Nebula in X-Rays)
1999年09月29日:X-射线波段的蟹状星云-(The Crab Nebula in X-Rays)--原图下载{mtitle title="X-射线波段的蟹状星云"/}Credit: Chandra X-ray Observatory,NASA说明: 为什么蟹状星云 (Crab Nebula)仍然不断地发出辉光?一次发生在西元1054年 (北宋至和元年) 的超新星爆炸,形成了蟹状星云。到现在,它仍然在各种颜色甚至整个电磁辐射频谱,发出很明亮的辐射。星云的中心是一个超级緻密的中子星,它每秒旋转30次。旋转的中子星不停地辐射能量,也使得它的转速慢了下来。中子星每秒传给星云的能量,和蟹状星云每秒向外辐射的能量相同。不久前发射的钱卓拉X-射线观测站 (Chandra X-Ray Observatory)所拍摄的这张照片里,我们在X-射线波段,能够看到中心区以前没有见过的细微结构。这种新观测,可能可以对中子星如何把能量传给星云,提供重要的线索。 照片里可以清楚看见高能粒子所形成的环状结构,这些高能粒子正以接近光速的高度,从中心区飞出来。除此之外,也可以看到从极区射出的强烈喷流。蟹状星云的中子星,每秒钟传给四週云气的能量大约是地球闪电的三千万倍,而且能量转移的效率几近完美。天文物理学家不停地研究这个不寻常的引擎,并且获益不少。{lamp/}原文:{mtitle title="The Crab Nebula in X-Rays"/}Credit: Chandra X-ray Observatory,NASAExplanation: Why does the Crab Nebula still glow? In the year 1054 A.D. a supernova was observed that left a nebula that even today glows brightly in every color possible, across the entire electromagnetic spectrum. At the nebula's center is an ultra-dense neutron star that rotates 30 times a second. The power liberated as this neutron star slows its rotation matches the power radiated by the Crab Nebula. The above picture by the recently launched Chandra X-Ray Observatory shows new details of the nebula's center in X-ray light, yielding important clues to how the neutron star powers the nebula. Visible are rings of high-energy particles that are being flung outward near light-speed from the center, and powerful jets emerging from the poles. Astrophysicists continue to study and learn from this unusual engine which continually transfers 30 million times more power than lightning at nearly perfect efficiency.
1999年09月29日
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1999-06-08
1999年06月08日:三裂星云的气柱和喷流-(Trifid Pillars & Jets)
1999年06月08日:三裂星云的气柱和喷流-(Trifid Pillars & Jets)--原图下载{mtitle title="三裂星云的气柱和喷流"/}Credit: J. Hester(Arizona St. U) et al.,WFPC2,HST,NASA说明: 尘埃柱就像是星际山峰,它们能残存下来,主要是因为它们的密度比周围高。但是在恶劣的环境中,它们还是会慢慢地被侵蚀掉。 在上面这张照片里,可以看到三裂星云一支巨大气体和尘埃柱的顶部,以及,一支向上指的小柱子和一个不寻常喷流 (喷向左方)。照片里粉红色的光点,是刚诞生的小质量恒星。位在右上方一颗巨大亮星 (不在这张照片上) 的辐射,正慢慢地把小柱子顶部的恒星,所吸积的气体给剥夺走。喷流延伸将近一光年远,不过如果没有外部光源的照射,应该是看不见的。 随着气柱的气体和尘埃持续地被蒸发掉,也许再过二万年,喷流的源头可能就会外露出来。{lamp/}原文:{mtitle title="Trifid Pillars & Jets"/}Credit: J. Hester(Arizona St. U) et al.,WFPC2,HST,NASAExplanation: Dust pillars are like interstellar mountains. They survive because they are more dense than their surroundings, but they are being slowly eroded away by a hostile environment. Visible in the above picture is the end of a huge gas and dust pillar in the Trifid Nebula, punctuated by a smaller pillar pointing up and an unusual jet pointing to the left. The pink dots are newly formed low-mass stars.A star near the small pillar's end is slowly being stripped of its accreting gas by radiation from a tremendously brighter star situated off the above picture to the upper right. The jet extends nearly a light-year and would not be visible without external illumination. As gas and dust evaporate from the pillars, the hidden stellar source of this jet will likely be uncovered, possibly over the next 20,000 years.
1999年06月08日
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