Astrophysics (Index)About

Wilson-Bappu effect

(a relation between a star's spectral line and luminosity)

The Wilson-Bappu effect is a relation between the luminosity of cool stars (G-type star, K-type star and red-giant M-type star) and the width (line broadening) of a particular emission line: the Ca II K line (ionized calcium, 393.366 nm), a width is referred to as W0. The relation provides a means of stellar distance determination.


(stars,relation)
Further reading:
http://en.wikipedia.org/wiki/Wilson-Bappu_effect
https://ui.adsabs.harvard.edu/abs/1957ApJ...125..661W/abstract
WaveLFreqPhoton
Energy
  
393.366nm762THz3.2eVWilson-Bappu effect

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