chromospheric activity

chromospheric activity

(kroh-mŏ-sfe -rik) The collection of phenomena displayed by certain types of single and binary stars, including flare stars, RS Canum Venaticorum stars, and T Tauri stars. The phenomena are similar to but usually much more extreme than solar activity, and are thought to require rapid rotation and a deep convective outer envelope. They include mass loss in stellar winds, starspots, rapid solarlike flares, and long-term cycles of activity analogous to the solar cycle (see sunspot cycle).
References in periodicals archive ?
RS CVn type stars show optical variability (outside eclipses) which is characterised by an amplitude up to 0.6 mag in the V band and interpreted as the rotationally modulated effect of cool spots on their surfaces, a result of increased chromospheric activity. The X-ray emission is an indicator of an active coronal region believed to be the result of rapid rotation and enhanced magnetic fields.
Among the topics are gravitational wave foreground radiation from neutron star-dwarf binaries, the chromospheric activity of late-type stars of the different rotational periods, spectrophotometry and model atmosphere flux fitting, the light-time effect and tertiary companions in close binary stars, the age of the local interstellar bubble, and the current status and outreach activities of radio astronomy in Malaysia.
As this binary has a spectral classification of G4V I suggest the dip in the light curve is due to chromospheric activity. This was not included in the model as PHOEBE (private communication from Andrej Prsa) encounters problems when working with spotting activity, which is evident from the synthetic light curve.
Analysis indicates that the star has chromospheric activity similar to stars in the Hyades Cluster, which is about 700 million years old.
But, many types are listed in the introduction so you have to plough through them all to see if the one you want is described (it is; they are rotating dwarfs of low amplitude with the light variations caused by spots, flares and chromospheric activity).
Abstract: In a classic 1972 paper, Andrew Skumanich showed that stellar rotation decreases over time--as does chromospheric activity, a proxy for magnetic field strength.