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
来源链接

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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A Geocentric chart from 1568

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图注： This map, created in 1568 by the Portuguese cartographer Bartolomeu Velho, depicts the worldview of the time, when many scholars believed in a geocentric model of the cosmos — the idea that Earth sits at the centre of the Universe with the Sun, Moon, the five planets known at the time, and stars moving around it. The design and layout of this map were influenced by astronomical understanding rooted in geocentric thinking. The geocentric model was widely accepted for many centuries, especially in Europe, based on interpretations of celestial motions and philosophical traditions that placed Earth at the centre. It was only later, with observations by astronomers such as, Galileo Galilei, that this model was replaced by the heliocentric model, which places the Sun at the centre of the Solar System.
来源： Bartolomeu Velho
来源链接

词汇表: 地心说 , 科学模型

授权许可： 公共领域 公共领域 图标

文件 ( 图像 12.99 MB)

Conjunction of Mercury and Venus above the Moon

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图注： From the observing deck at the European Southern Observatory’s Paranal site in Chile, in March 2008, astronomers captured a conjunction of celestial objects—a moment when two or more astronomical objects appear close together in the sky as seen from Earth. In this scene, the innermost planets Mercury and Venus appear aligned above the Moon, forming a pattern against the sky just before dawn. Although they are at very different distances from Earth, the geometry of their orbits brought them into almost the same line of sight, creating this beautiful cosmic alignment. In the image, the bright crescent Moon is visible low in the sky near the horizon, forming the most prominent object in the lower part of the scene. Just above the Moon, the brighter planet Venus can be seen, while Mercury, fainter and further from the horizon, appears nearby in the upper part of the image.
来源： ESO/Y. Beletsky
来源链接

词汇表: 合

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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Rhea reappearing after occultation by Titan

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图注： On October 27, 2009, NASA’s Cassini spacecraft orbiting around Saturn captured this view of Saturn's moon Rhea as it began to emerge after being hidden by Saturn's largest moon Titan during an occultation. An occultation is a celestial event in which one object moves in front of another and temporarily blocks the first object from view. In this image, Titan — about 5,150 km across — was closer to the spacecraft at about 1 million km, while Rhea — roughly 1,528 km in diameter — was farther away at about 2.3 million km. Titan’s high-altitude atmospheric haze is visible as a faint glow around its limb, showing the difference in surface and atmospheric properties between these two moons. Scientists study occultations like this because watching how one moon disappears behind or reappears from another helps refine our understanding of their orbits and physical characteristics.
来源： NASA/JPL/Space Science Institute
来源链接

词汇表: 卫星 , 泰坦 , 掩星

授权许可： 公共领域 公共领域 图标

文件 ( 图像 85.73 kB)

智能手机日偏食合成图

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为 OAE 制作

图注： 2021年，美国缅因州见证了迷人的日偏食，这是一种天文奇观，月球从地球和太阳之间穿过，从地球看去，太阳发出的光被部分遮挡。这张图像使用了智能手机以及摄影师发明的名为“Solar Snap”的应用程序和滤镜，捕捉到了这一天象的各个阶段。需要注意的是，观测日食时应佩戴合适的护目镜，以避免直视太阳对眼睛造成的伤害。日食期间，月球在其轨道上到达地球和太阳之间的某一点，从而部分或完全覆盖太阳圆面，具体取决于它们的相对位置。这张合成图像无缝结合了六个不同的时刻，展现了月球逐渐穿过太阳圆面的过程。每一弯月牙形的太阳，都展现了这迷人事件的一个独特阶段，让我们稍纵即逝地领略到自然世界的奇妙。智能手机等便捷工具，结合适当的应用程序和滤镜，使每个人都能够安全地记录并珍惜这些非凡的天象。
来源： Douglas Duncan/IAU OAE (CC BY 4.0)

词汇表: 日偏食
分类： 肉眼天文学 , 太阳系
标签： astrophotography

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

此文件在 Zenodo 上 ( 图像 465.84 kB)