Gómez de Castro, Ana Inés Física de la Tierra, Astronomía y Astrofísica, Universidad Complutense de Madrid, Madrid, Spain.
Show previous versions
- Solar systems
- Interstellar medium
- Stellar astronomy
- Extreme environments
- Links to Primary Literature
- Additional Readings
The study of astronomical objects by means of information obtained from the ultraviolet wavelength range of the electromagnetic spectrum. Ultraviolet light is more energetic than the visible light our eyes see, possessing a wavelength in the approximate range between approximately 10 and 320 nanometers. Many of the most abundant atoms in the universe emit light in this range when their energy states are changed, up to temperatures as high as a million K (about 1 million Celsius or 1.8 million Fahrenheit), above which x-rays and gamma rays become the main radiation emissions. Molecular gas is also very sensitive to ultraviolet radiation, since the electronic transitions of the most abundant molecules, including H2, CO, OH, CS, CO2 +, and C2, are in this range. Overall, ultraviolet observations are the most sensitive means of detecting and measuring the properties of diffuse matter in the universe over a very wide range of physical conditions, from the warm gas evaporating from exoplanets to the hot gas in the intergalactic medium and in supernova remnants, and the rise of energetic stars in new populations within galaxies (Fig. 1). Moreover, ultraviolet radiation from astronomical sources is a powerful ionizing agent, which helps drive astrochemistry and chemical evolution in developing planetary systems. See also: Astronomical spectroscopy; Astronomical imaging; Atom; Electromagnetic radiation; Exoplanets; Galaxy; Gamma-ray astronomy; Molecule; X-ray astronomy
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
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. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 39 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews 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 17,000 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