Calcium triplet

The infrared Ca II triplet, commonly known as the calcium triplet, is a set of three ionized calcium spectral lines at the wavelengths of 8498 Å, 8542 Å and 8662 Å (measured in air). The triplet is most often observed in absorption in the spectra of stars of spectral type G, K and M. Some Be stars, which are hot stars with hydrogen emission lines, show the calcium triplet in emission. The emission seems to come from peculiar properties of the gas disk that surrounds the star and produces the hydrogen emission lines.


See also

References

  1. ↑ Andretta; Busà; Gomez; Terranegra (2005). "The Ca II Infrared Triplet as a stellar activity diagnostic" (PDF). Astronomy & Astrophysics. p. 669.
  2. ↑ Jonathan Tennyson (2005). "Astronomical Spectroscopy. An introduction to the atomic and molecular physics in astronomical spectra" (PDF). Imperial College Press. p. 94. Archived from the original (PDF) on 2016-01-16. Retrieved 2016-07-09.
  3. ↑ G. Kordopatis, A. Recio-Blanco, P. de Laverny, A. Bijaoui, V. Hill, G. Gilmore, R. F. G. Wyse and C. Ordenovic (2011). "Automatic stellar spectra parameterisation in the IR Ca ii triplet region" (PDF). Astronomy & Astrophysics. p. 535, A106. Archived from the original on 2011-11-21.{{cite web}}: CS1 maint: multiple names: authors list (link)
  4. ↑ Polidan, R. S.; et al. (1976). "On the Detection of Binary be Stars" (PDF). Be and Shell Stars: IAU Symposium No. 70. 70: 405. Bibcode:1976IAUS...70..401P.
  5. ↑ Koubský, Pavel; et al. (2012). "Calcium Emission in Interacting Binary Be Stars". arXiv:1205.2259 [astro-ph.SR].