chromospheric activity index
(S-index, Mount Wilson S-index, flux 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#Stellar_chromospheres
https://exoplanetarchive.ipac.caltech.edu/docs/planets_help.html
http://www.astrosurf.com/buil/chromospheric_activity/
https://ui.adsabs.harvard.edu/abs/1995ApJ...438..269B/abstract
https://ui.adsabs.harvard.edu/abs/2017ApJ...835...25E/abstract
https://ui.adsabs.harvard.edu/abs/1978PASP...90..267V/abstract
https://ui.adsabs.harvard.edu/abs/1980PASP...92..385V/abstract
https://ui.adsabs.harvard.edu/abs/1968ApJ...153..221W/abstract
Index