Publication Date:
2019-06-28
Description:
Consideration is given to the different roles that magnetic fields play in the control of the structure and energy balance in the chromospheres and transition regions of late-type stars, in view of IUE and Einstein satellite observations. The rotational modulation of structures ('plages') that are bright in UV emission lines and overlie dark star spots suggests that magnetic flux tubes are the dominant structural elements in late-type stellar atmospheres, as well. It is proposed that the existence of a boundary between solar-type stars and those with little or no plasma, as well as the different types of G-K giants and supergiants, may be understood in terms of the fractional surface coverage by closed magnetic structures. Models computed for active and quiet regions of the sun are compared with those for active and quiet stars.
Keywords:
ASTROPHYSICS
Format:
text
