Chromospheres of late-type active and quiescent dwarfs. II - an activity index derived from profiles of the CA II 8498 A and 8542 A triplet lines

Bibcode
1989A&AS...80..189F
Foing, B. H.; Crivellari, L.; Vladilo, G.; Rebolo, R.; Beckman, J. E.
Bibliographical reference

Astronomy and Astrophysics Supplement Series (ISSN 0365-0138), vol. 80, no. 2, Oct. 1989, p. 189-200. Research supported by EEC.

Advertised on:
10
1989
Number of authors
5
IAC number of authors
2
Citations
35
Refereed citations
34
Description
High resolution, high signal to noise spectral profiles of the 8498 and 8542 A lines of the Ca II infrared triplet (IRT) have been obtained for a sample of late type dwarfs, with a wide range of levels of chromospheric activity, in the spectral range F9 to K4/5. These profiles, and the difference profiles for selected active and quiescent objects of corresponding spectral type are presented. After absolute calibration in flux, advantage is taken of the high resolution and S/N ratios of the spectra to define several IRT indices of chromospheric activity, for a set of bandwidths between 0.2 A and 1 A about the line centers. Excellent correlations for active stars between the IRT and the Ca H indices and between the respective line widths are shown, which pertain despite the different depths of formation of the lines in the stellar chromospheres.
Type
Refereed

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