Wavelength of the Sun's Peak Radiation Output

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Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
Beichner, Robert & Serway, Raymond Physics for Scientists And Engineers with Modern Physics Fifth Edition. Orlando, FL: Saunders College Publishing, 2000. "The surface temperature of the sun us about 6000K … From Wien's Displacement law,

λ = 2.898 mm·K / 6000 K = 483 nm

This wavelength is in the middle of the visible spectrum."
483 nm
"The Sun." Macmillian Encyclopedia of Earth Sciences New York: Simon & Schuster Macmillian Publishing, 1996. "This radiation spans the ultraviolet to far-infrared wavelength of about 0.5 microns." 500 nm
"Solar Spectral Irradiance" Handbook of Chemistry and Physics 82nd Edition Boca Raton, FL: CRC Press 2001. [Chart Irradiance vs. Wavelength
peak at approximately 0.475 microns]
475 nm
Appendix A: THE SUN. NASA Project SUN Handbook Version IV, August 1998. "We call this simple relation, 'Wien's Displacement Law'. It is very simple. We can write it as
W T = Constant
where
W = Wavelength (Angstroms)
T = Temperature (Degree Kelvin)
Constant = 2.898 × 107

This means if we observe the color of a star, we can estimate it surface temperature, or it we know the surface temperature we can predict its color. For our Sun, let us use 5750 K. Using this equation we get
W = Constant/T
W = 2.898 × 107 / 5750
W = 5040 Angstrom"
504 nm
Chaisson, Eric & McMillan, Steve Astronomy Today New Jersey: Prentice Hall Inc. 1993. "… Wien's Law: peak wavelength = 0.29 cm/T in the core of the sun, where the temperature is 107 K. just below the photosphere, where the temperature is 104 K." 0.29 nm
(core)

290 nm
(surface)

The Sun, Earth's closest star, is a source of a vast amount of power in our solar system, emitting a great deal of radiation to its surroundings. Whether this output is in a form recognizable to the naked eye or not, the sun gives off a variety of different waves, including anything from radio waves to gamma rays, varying a great deal in the energy and wavelength of each emission. The various wavelengths of radiation emitted by the sun is largely due to the temperature of the different portions of the sun; each zone emitting its own span of wavelengths, depending on its temperature. According to Wien's Law, established in 1893 by Wilhem Franz Wien, the peak wavelength of a continuous spectrum emitted by a blackbody multiplied by its temperature (in kelvin) is equal to a constant (λpeak T = 2.898x10-3 m·K. The formula also shows that peak wavelength is inversely proportional to temperature. Rearranging Wien's law reveals that

λpeak = (2.898 × 10-3m·K)/(T in kelvin)
for a blackbody radiator

The maximum wavelength output from the surface of the sun (originating from the photosphere) is approximately 500 nanometers (varying from exact measurements of 483 to 520 nm, depending on the temperature used to represent the surface of the sun, which is not clearly defined), while wavelength output from the inner zones are as short as (or even shorter than) 2.9 × 10-10 m (0.29 nm, which is located in the gamma ray portion of the electromagnetic spectrum). The max wavelength outputs vary along this wide range because the peak wavelength relies directly on the temperature of the blackbody, where higher temperatures lead to shorter peak wavelengths.

Tahir Ahmed -- 2002


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