天文学家如何测量一个星系的红移？
How do astronomers measure a galaxy's redshift?
把星系的光谱与实验室已知谱线对比，若特征线整体向长波（红）端偏移，偏移量除以原波长就是红移 z，可换算出退行速度和距离。
By comparing a galaxy's spectrum with known lab lines, the shift of features toward longer (red) wavelengths gives redshift z as the offset divided by the rest wavelength, from which recession speed and distance follow.
难度 专业 · 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
#红移 #光谱 #距离
为什么要在太空放“望远镜星座”而不是一台大望远镜？
Why place telescope 'constellations' in space instead of one big telescope?
多台小望远镜协同可形成等效大口径、还能同时覆盖多波段与广视场，成本与可靠性更优。
Multiple small telescopes together mimic a large aperture and cover more bands and field at better cost and reliability.
难度 专业 · 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
#望远镜阵列 #协同
天文观测数据为什么要做校准？
Why must astronomical data be calibrated?
望远镜、大气和探测器会引入偏差和噪声，校准用标准星和暗场、平场等校正响应，把原始计数转换成可靠的天体亮度与颜色。
Telescopes, atmosphere, and detectors add bias and noise; calibration with standard stars and dark/flat frames corrects the response, turning raw counts into reliable brightness and color.
难度 专业 · 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
#校准 #数据处理 #观测
为什么专业望远镜常用“自适应光学”？
Why do pro telescopes use adaptive optics?
它用可变形镜面实时抵消大气湍流造成的抖动，让地面望远镜也能接近太空望远镜的清晰度。
It uses a deformable mirror to cancel atmospheric turbulence in real time, letting ground telescopes approach space clarity.
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
#自适应光学 #大气
什么是偏振测量，它在天文中有何用？
What is polarimetry and what is it used for in astronomy?
偏振测量分析光波振动方向的偏好，可揭示尘埃排列、磁场方向与散射机制，用于研究恒星形成区、活动星系核喷流与系外大气。
Polarimetry analyzes the preferred direction of light's vibration, revealing dust alignment, magnetic-field direction and scattering; it is used for star-forming regions, AGN jets and exoplanet atmospheres.
难度 进阶 · 适合 初中(12-15)
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
#偏振 #磁场 #散射
多普勒效应除了测红移，还能测什么？
Besides redshift, what else can the Doppler effect measure?
通过分析谱线周期性的蓝移与红移，多普勒效应能测出恒星沿视线方向的运动速度，用于发现系外行星、双星和星系内的运动。
Periodic blue- and red-shifts in spectra let the Doppler effect measure line-of-sight velocity, used to find exoplanets, binary stars, and internal galaxy motions.
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
#多普勒 #速度 #视向
什么是光谱分辨率，它为何重要？
What is spectral resolution and why does it matter?
光谱分辨率是望远镜区分相邻波长的能力，分辨率越高越能分离密集谱线、精确测速度和化学丰度，是研究恒星与系外的关键指标。
Spectral resolution is a telescope's ability to separate nearby wavelengths; higher resolution resolves crowded lines and measures velocities and abundances precisely—key for stars and exoplanets.
难度 进阶 · 适合 初中(12-15)
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
#光谱分辨率 #谱线 #速度测量
多普勒红移和宇宙学红移是一回事吗？
Are Doppler redshift and cosmological redshift the same?
不是。多普勒红移来自天体相对运动，宇宙学红移来自空间自身膨胀拉长光波；遥远星系的红移主要是后者，需用广义相对论描述。
No. Doppler redshift comes from relative motion, while cosmological redshift comes from space itself expanding and stretching the light. Distant galaxies are dominated by the latter, described by general relativity.
难度 进阶 · 适合 初中(12-15)
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
#红移 #多普勒 #空间膨胀
什么是凌星光谱，如何用它找水？
What is transit spectroscopy and how does it find water?
行星凌星前后恒星光谱出现微小差别，来自穿过行星大气的光，借此在WASP-39b、K2-18b等大气中探测到水蒸气等分子。
Starlight spectra differ slightly before and during a planet's transit because light passes through its atmosphere, letting us detect molecules like water vapor in WASP-39b, K2-18b and others.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Seager 与 Sasselov,《Theoretical Transmission Spectra during Extrasolar Giant Planet Transits》,The Astrophysical Journal,2000 (DOI: 10.1086/309088)
Seager & Sasselov, 'Theoretical Transmission Spectra during Extrasolar Giant Planet Transits', The Astrophysical Journal, 2000, DOI: 10.1086/309088
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1086/309088
#凌星光谱 #水蒸气 #大气
天体光谱能告诉我们什么？
What can an astronomical spectrum tell us?
把星光按波长展开成光谱，亮暗吸收线对应特定元素和分子，借此可知天体的化学组成、温度、密度与磁场。
Spreading starlight into a spectrum, the bright and dark lines correspond to specific elements and molecules, revealing an object's chemical makeup, temperature, density and magnetic field.
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
#光谱 #吸收线 #化学成分