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absolute magnitude
absolute magnitude (symbol M)
1. The brightness that a star would have if it were at a distance of 10 parsecs in perfectly clear space without interstellar absorption. Absolute magnitude is usually deduced from the visual magnitude measured through a V filter, and is then written MV. If defined for another wavelength it carries a different subscript (U, B, etc.). When radiation at all wavelengths is included it becomes the absolute bolometric magnitude, Mbol. The Sun has an absolute magnitude of +4.8. Most other stars range between -9 (supergiants) and +19 (red dwarfs). 2. The brightness that a Solar System body would have if it were at a distance of 1 AU from both the Sun and Earth and fully illuminated by the Sun (i.e. with a phase angle of 0°). |
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Cite this article
"absolute magnitude." A Dictionary of Astronomy. 1997. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "absolute magnitude." A Dictionary of Astronomy. 1997. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O80-absolutemagnitude.html "absolute magnitude." A Dictionary of Astronomy. 1997. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-absolutemagnitude.html |
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absolute magnitude
absolute magnitude see magnitude . |
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Cite this article
"absolute magnitude." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "absolute magnitude." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1E1-X-absolmag.html "absolute magnitude." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-X-absolmag.html |
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