Three ionised calcium spectral lines at 8498 Å, 8542 Å and 8662 Å.
The infrared Ca II triplet, commonly known as the calcium triplet, is a triplet of three ionised calcium spectral lines at the wavelengths of 8498 Å, 8542 Å and 8662 Å (measured in air). The triplet has a strong emission,[1] and is most prominently observed in the absorption of spectral type G, K and M stars.[2][3][4]
See also
References