Article
Article
Fraunhofer lines
Article By:
Livingston, William C. National Solar Observatory, National Optical Astronomy Observatory, Tuscon, Arizona.
Last reviewed:June 2020
DOI:https://doi.org/10.1036/1097-8542.757204
Dark absorption features in the solar spectrum. They are named in honor of J. Fraunhofer, who first studied them in 1814 (see illustration). They are found from the ultraviolet at approximately 180 nanometers (nm) to the infrared at 20 micrometers (μm). Each line represents the net absorption of light by a particular atom or molecule. Most form in the Sun's atmosphere, although the Earth's telluric spectrum contributes lines of molecular oxygen (O2), carbon monoxide (CO), and other molecules. Some lines such as Fraunhofer's C line in the red (hydrogen-alpha) can be seen with a pocket spectroscope. Powerful research instruments reveal millions of lines, most of which are weak and blended together in an almost inextricable tangle. The table lists some interesting Fraunhofer lines.
The content above is only an excerpt.
About AccessScience
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 46 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information
