X-Nico

unusual facts about absorption line



Alpha Arae

The 'n' notation in the suffix indicates that the absorption lines in the star's spectrum appear spread out and nebulous because of the Doppler effect from rapid rotation.

Fraunhofer lines

The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun.


see also

Tunable diode laser absorption spectroscopy

Another way to measure the temperature is by relating the FWHM of the probed absorption line to the Doppler line width of the species at that temperature.