M45昴星团与壮丽的尘埃

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为 OAE 制作

图注： 2022年国际天文学联合会（IAU）OAE天文摄影比赛静态天体图案类别荣誉奖作品。 这张照片于2021年10 月在埃及西奈半岛圣凯瑟琳的达尔艾德拍摄，展示了昴星团——一个被俗称“七姐妹星”的疏散星团。 昴星团位于金牛座的西北部。金牛座源自古巴比伦人甚至苏美尔人的信仰，它被当时的人们称为天牛，是天神所拥有的强大生物。在巴比伦晚期，昴星团被称为“牛背上的鬃毛”。在中国，这个星宿也被称为“髦头“，但这并不一定意味着东亚和西亚对这个星宿的称呼有任何联系，尽管有人假设这两个文明通过丝绸之路的建立而进行了交流。 在古巴比伦的文献中，并没有出现将昴星团称为“毛发”的记载。相反，昴星团在苏美尔语中被称为“星团”，而苏美尔语中的这个词被后来的语言作为借词所引入。苏美尔和巴比伦早期的宗教将所有星座与特定的神灵联系在一起，包括天神、恶魔、神使。昴星团与一位被称为“七”的冥界神灵有关，被认为是七种会说话的武器或全副武装的神灵的集合体。后来希腊人将其命名为“七姐妹星”，可能是源于不同文化间对这一古老宗教联系的误解，因为事实上并不能在这个星团中看到七颗星。 昴星团在天空中确实非常显眼，因此被用于多种文化目的，如确定历法和春分。然而，在文化天文学中，它的重要性经常被夸大。由于用七个圆点表示昴星团的传统源于古代苏美尔信仰，因此将石器时代以来欧洲、亚洲和美洲的洞穴墙壁和考古遗址上的七个圆点解释为昴宿星团时，我们应该慎重起见。 现代天体物理学发现，昴星团非常年轻，因此在古代肯定没有额外的恒星。此外，我们还知道，昴星团中所见的明亮恒星只是整个疏散星团的核心区域，该星团其实由散布在天空中的数百颗恒星组成，在任何方向的延展尺度都超过明亮核心的一到两个直径。这张照片甚至没有显示出整个星团。昴星团距离地球大约400光年，从天文学的角度来说是比较近的。
来源： Mohamed Usama/IAU OAE

词汇表: 星团 , 梅西耶天体 , 尘埃云 , 气体云 , 星际介质 , 疏散星团 , 昴宿星团
分类： 银河系与星际介质 , 肉眼天文学 , 恒星

授权许可： 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 图标

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The Horsehead Nebula

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图注： This image shows the Horsehead Nebula, located at a distance of about 1,300 light-years from Earth in the Orion constellation, one of the most iconic examples of a dark nebula. A dark nebula is a dense cloud of interstellar dust and cold gas that absorbs and scatters visible light, preventing background stars and glowing gas from reaching our eyes. This false-color image combines data captured through multiple narrowband filters, each isolating light from different elements in the nebula. The dark, horse-shaped silhouette appears sharply outlined against the luminous nebula behind it, where energetic radiation from nearby young stars causes the gas to glow. The uneven distribution of visible stars in this image is not random: regions rich in dust in the lower part of this image appear almost empty, while clearer areas reveal many background stars. The dust acts like a cosmic curtain, hiding stars that lie behind it while allowing stars in front of the cloud to remain visible. Studying such regions helps astronomers understand how nebulae serve as environments where new stars can form.
来源： T.A.Rector (NOIRLab/NSF/AURA) and Hubble Heritage Team (STScI/AURA/NASA)
来源链接

词汇表: 暗星云 , 灰尘 , 星云 , 空间

授权许可： 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 图标

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The LDN 483 Dark Nebula

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图注： This image shows a dark molecular cloud known as LDN 483, captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. At first glance, the patch of sky looks like a region where stars are missing, but the effect is due to interstellar extinction — dust and gas within LDN 483 absorb and scatter light from background stars, making them appear faint or invisible to telescopes that observe visible light. Interstellar extinction is the dimming of light from distant objects caused by dust and gas between the object and the observer, a common phenomenon in astronomy that must be accounted for when measuring stellar brightness and color. Dark nebulae like LDN 483 are dense concentrations of interstellar matter located within our Milky Way Galaxy. This particular cloud lies about 700 light-years from Earth in the constellation Serpens and contains enough material to block most visible light from stars behind it. Because dust grains preferentially scatter shorter (bluer) wavelengths of light, extinction can also make objects appear redder than they truly are — a related effect known as interstellar reddening. Understanding and correcting for extinction is essential for astronomers to reveal the true brightness, distance, and physical properties of celestial objects seen through dusty regions of space.
来源： ESO
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词汇表: 暗星云 , 星际介质 , 星际消光

授权许可： 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 图标

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Dust Clouds and Nebulae near R Coronae Australis

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图注： The image shows a dark and dusty cloud and some bright reflection nebulae near the binary star R Coronae Australis. The dark cloud spans several light-years and is located in the constellation Corona Australis near the constellation Sagittarius, in the direction of the Milky Way's center. The cloud appears to swallow the light of distant stars behind it as the dust particles in it scatter light passing through in all directions. This gives it the appearance of a void in the sky. This dark nebula is part of the broader Corona Australis Molecular Clouds. R Coronae Australis forms part of the Coronet Cluster, a collection of young stars which formed at some point in the last two million years. Around R Coronae Australis in the center of the image is the small reflection nebula NGC 6729 with two blueish reflection nebulae NGC 6726 and NGC 6727 lying to the upper right of it. In these nebulae the dust scatters light from bright stars near the nebula towards an observer on Earth, making it glow in this image.
来源： ESO
来源链接

词汇表: 暗星云 , 灰尘 , 星云 , 星际介质 , 星际消光 , 分子云
分类： 银河系与星际介质

授权许可： 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 图标

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Herschel’s view of new stars and molecular clouds

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图注： This image shows the Westerhout 3, 4 and 5 star formation regions. This area has huge amounts of gas and dust. This gas and dust hides the physical processes going on in this region from studies using visible light. This image was taken in infrared light by the Herschel Space Observatory. This infrared light allowed Herschel to see deep into these star forming regions. In Westerhout 3, 4 and 5, huge, cold clouds of molecular hydrogen have collapsed into dense knots and filaments. Within these new structures the gas is dense and cold enough for it to collapse and form stars. These new stars give off powerful winds of charged particles, like stronger versions of the solar wind our sun gives off. These winds have combined to blow massive bubbles in the surrounding gas and dust. These are visible as the large darker voids in the image.
来源： ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech)
来源链接

词汇表: 红外天文学 , 恒星形成 , 星际介质 , 分子云 , 星风
分类： 银河系与星际介质 , 恒星

授权许可： 知识共享许可协议 Attribution 3.0 IGO 知识共享许可协议 Attribution 3.0 IGO 图标

文件 ( 图像 4.53 MB)