Magnetic Doppler Imaging and UV Emission of an Active K Dwarf
Abstract
Our objective is to determine, for the first time ever, the functional and spatial relationships between magnetic flux, outer atmospheric emission, and temperature inhomogeneities on the surface of an active cool dwarf star. We have developed and successfully tested a new method, magnetic doppler imaging, for mapping the surface temperature and magnetic field distributions on rapid rotators. We will apply this method to the young, rapidly rotating, spotted K2 dwarf, HD 82558, covering the star with a phase resolution of 0.1 over two full rotations. The second rotation is crucial for separating out the effects of flares and/or active region evolution. The UV spectra will be combined with EUVE and ROSAT data to determine the longitudinal extent and the brightness of stellar active regions from the photosphere to the corona. These surface brightness maps will be directly compared with the magnetic flux and temperature maps to study stellar plage/spot properties, and serve as a basis for more realistic two-component models (quiet +plage/spot) for the outer atmospheres of active solar-like dwarfs.
- Publication:
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IUE Proposal
- Pub Date:
- 1993
- Bibcode:
- 1993iue..prop.4584S