Glossary term: 光譜

Redirected from 吸收線

Description: 光穿過水滴，光線將分成紫色、藍色、綠色到黃色、橙色和紅色的基本顏色，這就形成了彩虹。每種顏色對應一個波長範圍，彩虹的顏色是按照從紫到紅的波長遞增順序排列的。這種按波長分解的光（或更一般的說法，電磁輻射）被稱為光譜。

電磁輻射是由被稱為“光子”的光粒子混合而成的。光譜相當於按能量對光子進行分類，並記錄每個特定能量範圍內有多少光子。根據量子力學的基本定律，這等同於按頻率對光進行分類——這是描述光譜的另一種方式。

如果能量隨波長（或光子能量，或頻率）的變化平滑變化，則稱為連續光譜。與此相反，光譜中某些波長處的尖銳凹陷或峰值分別稱為吸收線和發射線。這些線是由於原子或分子（甚至原子核）內部不同能級之間的躍遷而產生的，它們會吸收或發射特定波長的輻射。例如，在可見光中，恆星會顯示出帶有吸收線的連續光譜。這些吸收線包含恆星化學成分的信息。對光譜的分析稱為光譜學；能夠記錄光譜的儀器稱為光譜儀、分光計或攝譜儀。

Related Terms:

See this term in other languages

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

This is an automated transliteration of the simplified Chinese translation of this term

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".

If you notice a factual or translation error in this glossary term or definition then please get in touch.

Related Media

彩虹的24小時

Caption: 這幅全景圖是在意大利裡窩那用智能手機拍攝的，展示了在2021年12月的三個不同日期分別捕捉到的一系列鮮豔彩虹。彩虹是懸浮在空中的水滴折射陽光所形成的，通常在降雨後或霧氣彌漫時出現。水滴就像稜鏡一樣，將陽光分解（折射）成各種顏色。不同波長的光被折射的程度不同，這就是我們看到這樣的顏色層次的原因。攝影師巧妙地合併了不同日期拍攝的最引人注目的照片，以突出這些彩虹的不同大小和光彩。由於每道彩虹出現時太陽在天空中的位置不同，因此彩虹的中心位置也不同。這張合成照片完美地捕捉到了彩虹瞬息萬變卻又令人著迷的魅力，展示了彩虹受大氣條件變化的影響而瞬間出現又逐漸消散的過程。
Credit: Fabrizio Guasconi/IAU OAE (CC BY 4.0)

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

Related Diagrams

A smooth line declining at longer wavelengths with a few sharp dips.

Spectrum of an O-type star

Caption: The spectrum of the O-type star HD 235673 with wavelength in nanometers on the x-axis and flux on the y-axis. The top part of the plot shows the same spectrum but with bright patches for wavelengths with high flux and dark patches for wavelengths with low flux. The colour of the line between 400 nm and 700 nm roughly corresponds to the colour the human eye would see light of that wavelength. Below 400 nm and above 700 nm, where the human eye can see little to no light, the lines are coloured blue and red respectively. The black lines show spectral absorption lines caused by atoms and ions of different elements in the star’s atmosphere. These atoms and ions absorb at specific wavelengths, causing sharp, dark lines in the spectra. How strong these lines are depends on the temperature of the star’s atmosphere. Two stars made from the same mix of elements could have spectra with vastly different sets of lines in their spectra if they have different temperatures in their atmospheres. For O-type stars the most important features are a small number of lines caused by ionized helium. These lines are stronger in O-type stars than in cooler stars. Lines from helium atoms and hydrogen atoms also appear in the spectrum. The spectrum has more flux at the blue end of the spectrum than at the red end of the spectrum.
Credit: IAU OAE/SDSS/Niall Deacon

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

Spectrum of a B-type star

Caption: The spectrum of the B-type star HD 258982. The colour of the line between 400 nm and 700 nm roughly corresponds to the colour the human eye would see light of that wavelength. Below 400 nm and above 700 nm, where the human eye can see little to no light, the lines are coloured blue and red respectively. The black lines show spectral absorption lines caused by atoms and ions of different elements in the star’s atmosphere. These atoms and ions absorb at specific wavelengths, causing sharp, dark lines in the spectra. How strong these lines are depends on the temperature of the star’s atmosphere. Two stars made from the same mix of elements could have spectra with vastly different sets of lines in their spectra if they have different temperatures in their atmospheres. For B-type stars the most important lines are caused by helium atoms. These lines are strongest in B-type stars and weaker in hotter and cooler types. Lines from hydrogen atoms are also present but are not as strong as in cooler A-type stars.
Credit: IAU OAE/SDSS/Niall Deacon

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

A smooth line peaking about 420 nm then declining at longer wavelengths with a few fairly broad dips.

Spectrum of an A-type star

Caption: The spectrum of the A-type star BD-11 1212. The colour of the line between 400 nm and 700 nm roughly corresponds to the colour the human eye would see light of that wavelength. Below 400 nm and above 700 nm, where the human eye can see little to no light, the lines are coloured blue and red respectively. The black lines show spectral absorption lines caused by atoms and ions of different elements in the star’s atmosphere. These atoms and ions absorb at specific wavelengths, causing sharp, dark lines in the spectra. How strong these lines are depends on the temperature of the star’s atmosphere. Two stars made from the same mix of elements could have spectra with vastly different sets of lines in their spectra if they have different temperatures in their atmospheres. Lines from hydrogen atoms dominate the spectra of A-type stars and are strongest at this spectral type.
Credit: IAU OAE/SDSS/Niall Deacon

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

A relatively smooth line peaking about 430 nm then declining at longer wavelengths with a few fairly broad dips.

Spectrum of an F-type star

Caption: The spectrum of the F-type star 2MASS J22243289+4937443. The colour of the line between 400 nm and 700 nm roughly corresponds to the colour the human eye would see light of that wavelength. Below 400 nm and above 700 nm, where the human eye can see little to no light, the lines are coloured blue and red respectively. The black lines show spectral absorption lines caused by atoms and ions of different elements in the star’s atmosphere. These atoms and ions absorb at specific wavelengths, causing sharp, dark lines in the spectra. How strong these lines are depends on the temperature of the star’s atmosphere. Two stars made from the same mix of elements could have spectra with vastly different sets of lines in their spectra if they have different temperatures in their atmospheres. The lines from hydrogen atoms that are strongest in A-type stars are still relatively strong in F-type stars but lines from metals, particularly ionised calcium begin to become strong at this spectral type.
Credit: IAU OAE/SDSS/Niall Deacon

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

A quite ragged line peaking about 470 nm then declining at longer wavelengths with a few deeper dips.

Spectrum of a G-type star

Caption: The spectrum of the G-type star UCAC4 700-069569. The colour of the line between 400 nm and 700 nm roughly corresponds to the colour the human eye would see light of that wavelength. Below 400 nm and above 700 nm, where the human eye can see little to no light, the lines are coloured blue and red respectively. The black lines show spectral absorption lines caused by atoms and ions of different elements in the star’s atmosphere. These atoms and ions absorb at specific wavelengths, causing sharp, dark lines in the spectra. How strong these lines are depends on the temperature of the star’s atmosphere. Two stars made from the same mix of elements could have spectra with vastly different sets of lines in their spectra if they have different temperatures in their atmospheres. In G-type stars lines from hydrogen atoms are weaker than in F-type stars and lines from ionised calcium stronger. Lines from metal atoms such as atoms of iron, sodium and calcium also begin to become prominent.
Credit: IAU OAE/SDSS/Niall Deacon

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

Browse all diagrams
for this term

Related Activities

Hunting for spectra

astroEDU educational activity (links to astroEDU website)
Description: Learn about light and spectra building a spectroscope with a CD!

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons
Tags: Hands-on , Experiment , prism
Age Ranges: 8-10 , 10-12 , 12-14 , 14-16 , 16-19
Education Level: Informal , Middle School , Primary , Secondary
Areas of Learning: Guided-discovery learning
Costs: Low Cost
Duration: 1 hour
Group Size: Individual
Skills: Asking questions , Constructing explanations , Planning and carrying out investigations

Reading the Rainbow

astroEDU educational activity (links to astroEDU website)
Description: By understanding how rainbows work, you can discover about light and its properties, learning about stars, nebulae, galaxies, and our Universe.

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons
Age Ranges: 14-16 , 16-19 , 19+
Education Level: Informal , Middle School , Secondary , University
Areas of Learning: Interactive Lecture , Observation based , Social Research
Costs: Low Cost
Duration: 1 hour 30 mins
Group Size: Group
Skills: Analysing and interpreting data , Asking questions , Engaging in argument from evidence

Find the hidden rainbows

astroEDU educational activity (links to astroEDU website)
Description: Let’s reveal hidden rainbows around us and the physical processes that make them!

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons
Age Ranges: 10-12 , 12-14 , 14-16
Education Level: Middle School , Secondary
Areas of Learning: Interactive Lecture , Observation based , Social Research
Costs: Medium Cost
Duration: 1 hour