什么是光谱，天文学家为什么重视它？
What is a spectrum and why do astronomers value it?
光谱是把光按波长展开后得到的彩虹状分布，其中包含暗线和亮线。每种元素只吸收或发射特定波长的光，因此光谱像指纹一样揭示天体的化学组成、温度和运动速度。没有光谱，我们就无法知道恒星和星系是由什么构成的。
A spectrum is light spread out by wavelength into a rainbow-like pattern with dark and bright lines. Each element absorbs or emits only specific wavelengths, so the spectrum reveals a body's chemical makeup, temperature, and motion like a fingerprint. Without spectra we could not know what stars and galaxies are made of.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Zeilik,《Astronomy: The Evolving Universe》第9版,Cambridge University Press,2002
M. Zeilik, Astronomy: The Evolving Universe, 9th ed., Cambridge University Press, 2002
#光谱 #元素指纹 #红移
射电望远镜是什么？
What is a radio telescope?
射电望远镜接收天体发出的无线电波而非可见光，通常用巨大的抛物面天线把信号汇聚到接收机。它能穿透尘埃看到被遮挡的星际区域，也用于探测脉冲星、星系和宇宙微波背景。著名的 FAST 天眼就是世界最大的单口径射电望远镜。
A radio telescope receives radio waves rather than visible light from celestial objects, usually with a large dish that focuses signals to a receiver. It can see through dust into hidden regions of the galaxy and detect pulsars, galaxies, and the cosmic microwave background. The famous FAST is the world's largest single-dish radio telescope.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#射电望远镜 #无线电波 #FAST
为什么很多天文台都建在高山上？
Why are many observatories built on mountains?
高山上空气稀薄、水汽少，大气更稳定，能减少光线的吸收和抖动，让星星看起来更清楚。远离城市还能避开光污染，使暗弱的天体也能被看见。因此世界大型光学望远镜多建在干燥的高原或火山顶。
High mountains have thin, dry, stable air that reduces absorption and wobble of light, making stars appear sharper. Being far from cities also avoids light pollution so faint objects are visible. That is why major optical telescopes are built on dry plateaus or volcano tops.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Zeilik,《Astronomy: The Evolving Universe》第9版,Cambridge University Press,2002
M. Zeilik, Astronomy: The Evolving Universe, 9th ed., Cambridge University Press, 2002
#天文台 #高山 #光污染
为什么星星有不同的亮度？
Why do stars have different brightnesses?
星星看起来明暗不同，既取决于它本身的发光能力（光度），也取决于它离我们有多远。本身很亮但极遥远的星，可能看起来和一颗较近的暗星差不多亮。天文学家用视星等描述看起来的亮度，用绝对星等描述真实发光能力。
Stars appear bright or dim depending both on their intrinsic luminosity and on their distance from us. A very luminous but extremely distant star can look as bright as a fainter nearby one. Astronomers use apparent magnitude for how bright it looks and absolute magnitude for its true output.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Zeilik,《Astronomy: The Evolving Universe》第9版,Cambridge University Press,2002
M. Zeilik, Astronomy: The Evolving Universe, 9th ed., Cambridge University Press, 2002
#星等 #光度 #距离
望远镜是怎么帮我们看见天体的？
How do telescopes help us see celestial objects?
望远镜用大镜片或天线收集比人眼多得多的光，再把光线汇聚、放大，使遥远暗淡的天体变得可见。它还能把光分解成光谱，告诉我们天体由什么构成。没有望远镜，人类无法了解银河系之外的世界。
A telescope uses large lenses or antennas to gather far more light than the human eye and then focuses and magnifies it, making distant faint objects visible. It can also split light into a spectrum that reveals what an object is made of. Without telescopes we could not study the universe beyond the Milky Way.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Zeilik,《Astronomy: The Evolving Universe》第9版,Cambridge University Press,2002
M. Zeilik, Astronomy: The Evolving Universe, 9th ed., Cambridge University Press, 2002
#望远镜 #聚光 #观测
为什么要在太空中放置望远镜？
Why place telescopes in space?
地球大气会吸收和扭曲许多波段的光，还会造成恒星闪烁、降低分辨率，使地面观测受限。太空望远镜在大气层之上工作，能接收被大气挡住的红外、紫外、X射线等，并获得不受扰动的高清晰图像。哈勃和韦伯望远镜就是典型例子。
Earth's atmosphere absorbs and distorts many wavelengths and causes twinkling that lowers resolution, limiting ground observations. A space telescope operates above the atmosphere, capturing infrared, ultraviolet, and X-rays blocked below, and gets undisturbed sharp images. Hubble and Webb are prime examples.
难度 入门 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Zeilik,《Astronomy: The Evolving Universe》第9版,Cambridge University Press,2002
M. Zeilik, Astronomy: The Evolving Universe, 9th ed., Cambridge University Press, 2002
#太空望远镜 #大气干扰 #波段
什么是天文干涉测量？
What is astronomical interferometry?
干涉测量把多台分开的望远镜接收到的光波精确合成，相当于造出一台口径等于望远镜间距的巨型虚拟望远镜。它能突破单台望远镜的分辨率极限，看清极细微的结构，例如事件视界望远镜就是用全球射电天线阵列拍下黑洞照片。
Interferometry precisely combines light waves from several separated telescopes, effectively creating a giant virtual telescope whose aperture equals the spacing between them. It surpasses the resolution limit of any single telescope and reveals extremely fine detail; the Event Horizon Telescope used a global radio array to image a black hole this way.
难度 入门 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Event Horizon Telescope Collaboration 2019, ApJL 875, L1；2022, ApJL 930, L12
Event Horizon Telescope Collaboration 2019, ApJL, 875, L1; 2022, ApJL, 930, L12
#干涉测量 #分辨率 #虚拟望远镜