Astrophysics (index)

H-alpha

(Ha)
(hydrogen line for electrons settling from n = 3 to n = 2.)

H-alpha (Ha, H-α) is the first line in the Balmer Series of Hydrogen (H) Spectral Lines. It has a wavelength of 656.3 nm and is red.

H-alpha is bright in the sky but does not stand out visually because it is so red as to be outside the most sensitive part of the eye's light sense.

An H-alpha filter is centered on the H-alpha Wavelength.


(Balmer Series,hydrogen,line,spectrum)
http://en.wikipedia.org/wiki/H-alpha
WaveLFreqPhoton
Energy
  
656nm457THz1.9eVH-alpha

Referenced by:
Balmer Series
Be Star
HII Region (HII)
Quasar (QSO)
Star Formation Rate (SFR)

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