Skip to main content
Select Source:

absorption spectrum

absorption spectrum A graph that shows the percentage of each wavelength of light absorbed by a pigment (e.g. chlorophyll, which absorbs mainly in the red and blue parts of the spectrum).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"absorption spectrum." A Dictionary of Ecology. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"absorption spectrum." A Dictionary of Ecology. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/absorption-spectrum

"absorption spectrum." A Dictionary of Ecology. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/absorption-spectrum

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

absorption spectrum

absorption spectrum A graph that shows the percentage of each wavelength of light absorbed by a pigment (e.g. chlorophyll, which absorbs mainly in the red and blue parts of the spectrum).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"absorption spectrum." A Dictionary of Plant Sciences. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"absorption spectrum." A Dictionary of Plant Sciences. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/absorption-spectrum-0

"absorption spectrum." A Dictionary of Plant Sciences. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/absorption-spectrum-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

absorption spectrum

absorption spectrum: see spectrum.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"absorption spectrum." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"absorption spectrum." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/absorption-spectrum

"absorption spectrum." The Columbia Encyclopedia, 6th ed.. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/absorption-spectrum

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Fraunhofer lines

Fraunhofer lines (froun´hôfər): see sun.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Fraunhofer lines." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"Fraunhofer lines." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/fraunhofer-lines

"Fraunhofer lines." The Columbia Encyclopedia, 6th ed.. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/fraunhofer-lines

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

absorption spectrum

absorption spectrum See spectrum.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"absorption spectrum." A Dictionary of Biology. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"absorption spectrum." A Dictionary of Biology. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/absorption-spectrum-1

"absorption spectrum." A Dictionary of Biology. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/absorption-spectrum-1

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Fraunhofer Lines

Fraunhofer Lines

Fraunhofer lines are dark (absorption) lines in the solar spectrum that can be seen when sunlight is passed through a prism or other device to separate it into its component wavelengths. They occur because cooler gas, which is higher in the suns atmosphere, absorbs some colors of the light emitted by hotter gas lower in the suns atmosphere.

Isaac Newton (16421727) discovered that if white light is passed through a prism, it separates into a rainbow, which is a spectrum of visible light frequencies. While studying the spectrum that sunlight made, Joseph Fraunhofer (17871826) discovered some dark lines scattered among the colors. These dark lines were segments of colors missing from the complete spectrum. Fraunhofer counted 574 of these lines, which we now call Fraunhofer lines. Today, using much more sophisticated techniques, astronomers have discovered tens of thousands of Fraunhofer lines. Why doesnt the sun emit these missing colors? Or, if the sun does emit these colors, what happens to the light before it reaches Earth? The answer lies at the surface of the sun.

When we look at a picture of the sun, the surface that we see is called the photosphere. The photosphere is a region, several hundred kilometers thick, in which the sun changes from opaque to transparent. It is not actually the outermost surface: the sun extends for thousands of kilometers beyond the photosphere, but it is not usually visible from earth. The photosphere is interesting because within this thin layer of the sun (thin compared to the whole sun, of course) sunlight is created, and some of the colors are lost almost immediately. The lower region of the photosphere has a temperature of about 10,000°F (about 5,500°C) and glows white-hot. Any object that glows due to a high temperature gives off a complete spectrum, that is, it has all the colors of the rainbow. As this light proceeds upwards in the sun into a higher region of the photosphere, the temperature drops several thousand degrees. Although most of the light passes right through, some of the light is absorbed by the cooler gas. Only certain colors are removed because the chemical elements in the photosphere can only absorb certain wavelengths of light, and different wavelengths correspond to different colors. For example, sodium absorbs some yellow light at a wavelength of about 5.89x10-7m. These absorbed colors cause the Fraunhofer lines. By measuring precisely the wavelengths of the missing colors, that is, the Fraunhofer lines, and how much light is actually absorbed, astronomers have learned much about the temperature inside the sun and its chemical composition.

We can also learn about other stars in the sky by looking at the absorption lines in their spectra. By studying the similarities and differences that they have with the Fraunhofer lines, we can learn study the similarities and differences between other stars and our Sun.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Fraunhofer Lines." The Gale Encyclopedia of Science. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"Fraunhofer Lines." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/fraunhofer-lines

"Fraunhofer Lines." The Gale Encyclopedia of Science. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/fraunhofer-lines

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Fraunhofer Lines

Fraunhofer lines

Fraunhofer lines are dark absorption lines in the solar spectrum that can be seen when sunlight is passed through a prism to separate it into the colors of the rainbow. They occur because cooler gas, which is higher in the Sun's atmosphere, absorbs some colors of the light emitted by hotter gas lower in the Sun's atmosphere. Sir Isaac Newton (1642-1727) discovered that if white light is passed through a prism, it separates into a rainbow, which is called a spectrum. While studying the spectrum that sunlight made, Joseph Fraunhofer (1787-1826) discovered some dark lines scattered among the colors. These dark lines were segments of colors missing from the complete spectrum. Fraunhofer counted 574 of these lines, which we now call Fraunhofer lines. Today, using much more sophisticated techniques, astronomers have discovered tens of thousands of Fraunhofer lines. Why doesn't the Sun emit these missing colors? Or, if the Sun does emit these colors, what happens to the light before it reaches Earth ? The answer lies at the surface of the Sun.

When we look at a picture of the Sun, the surface that we see is called the photosphere. The photosphere is a region, several hundred kilometers thick, in which the Sun changes from opaque to transparent. It is not actually the outermost surface: the Sun extends for thousands of kilometers beyond the photosphere, but it is not usually visible from Earth. The photosphere is interesting because within this thin layer of the Sun (thin compared to the whole Sun, of course) sunlight is created, and some of the colors are lost almost immediately. The lower region of the photosphere has a temperature of about 10,000o F (about 5,500o C) and glows white-hot. Any object that glows due to a high temperature gives off a complete spectrum, that is, it has all the colors of the rainbow. As this light proceeds upwards in the Sun into a higher region of the photosphere, the temperature drops several thousand degrees. Although most of the light passes right through, some of the light is absorbed by the cooler gas. Only certain colors are removed because the chemical elements in the photosphere can only absorb certain wavelengths of light, and different wavelengths correspond to different colors. For example, sodium absorbs some yellow light at a wavelength of about 5.89x10-7m. These absorbed colors cause the Fraunhofer lines. By measuring precisely the wavelengths of the missing colors, that is, the Fraunhofer lines, and how much light is actually absorbed, astronomers have learned much about the temperature inside the Sun and its chemical composition.

We can also learn about other stars in the sky by looking at the absorption lines in their spectra. By studying the similarities and differences that they have with the Fraunhofer lines, we can learn a lot about the similarities and differences that other stars have with our Sun.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Fraunhofer Lines." The Gale Encyclopedia of Science. . Encyclopedia.com. 11 Sep. 2018 <http://www.encyclopedia.com>.

"Fraunhofer Lines." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 11, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/fraunhofer-lines-0

"Fraunhofer Lines." The Gale Encyclopedia of Science. . Retrieved September 11, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/fraunhofer-lines-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.