Astrophysics (Index)About

chromospheric activity index

(S-index)
(measure of magnetic activity of a star's chromosphere)

The chromospheric activity index (or S-index) is a measure of the chromospheric magnetic field activity of a star. It is derivable from the star's spectroscopy, and is of interest regarding the Sun for comparison with other stars. A star's S-index changes over time, i.e., it is not a constant value.


(Sun,stars,magnetism,measure)
Further reading:
https://en.wikipedia.org/wiki/Chromosphere#On_other_stars
http://www.astrosurf.com/buil/chromospheric_activity/
https://ui.adsabs.harvard.edu/abs/1995ApJ...438..269B/abstract
https://ui.adsabs.harvard.edu/abs/2018A%26A...616A.108B/abstract

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