Astrophysics (index)about


(Ha, Hα, H-α)
(hydrogen line for electrons settling from n = 3 to n = 2)

H-alpha (Ha, , or H-α) is the first line in the Balmer Series of Hydrogen 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 (or Hydrogen-Alpha Filter) is centered on the H-alpha Wavelength.

(Balmer Series,hydrogen,line,spectrum)

Referenced by:
Balmer Series
Be Star
Dickel-Wendker-Bieritz Catalog (DWB)
HII Region (HII)
Palomar Four-Filter Survey (PC)
Quasar (QSO)
Star Formation Rate (SFR)
VLT Survey Telescope (VST)