SPECTRA & SPECTROSCOPY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site H-alpha A red spectral line, at 6563 Å (656.3 nanometers), emitted by a hydrogen atom when its electron falls from the third lowest energy level (n=3) to the second lowest energy level (n=2). The same line appears in absorption when electrons are raised from n=2 to n=3. Many solar features, such as prominences, show up best in H-alpha, so that, for observation of the Sun, filters are often used that allow only light close to the H-alpha wavelength to pass. H-alpha is the first member of the Balmer series. Related category    • SPECTRA AND SPECTROSCOPY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP