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| Paper: |
Photospheric Activity on a Young Sun Analog |
| Volume: |
448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun |
| Page: |
1131 |
| Authors: |
Gondoin, P.; Gandolfi, D.; Fridlund, M.; Guenter, E.; Hatzes, A. |
| Abstract: |
The solar surface differential rotation was initially discovered via the simple method of tracking the rotation rates of individual starspots at different latitudes. Adopting a similar principle and using a model based on the rotational modulation of the visibility of active regions, we analysed the high accuracy light curve of an active star observed with the CoRoT satellite.
Spectral determination of the effective temperature and surface gravity indicate that the object is located near the evolutionary track of a 1.1 M☉ pre-main sequence star at an age of approximately 13 Myrs.
Assuming a temperature difference of 800 K between the spots and the unperturbed photosphere, the variations of amplitude of the lightcurve can be interpreted as the result of an increase of the spot surface coverage from ∼17-24 % at the beginning of the CoRoT observing run to more than ∼43 %, 20 days later. The starspots used as tracers of the star rotation constrain the rotation period to 1.62 ± 0.02 days and do not show evidence for differential rotation.
We conclude that the high magnetic activity level and the fast rotation of the target star are manifestation of its stellar youth consistent with its estimated evolutionary status and with the detection of a strong Li I λ6708 Å absorption line in its spectrum. We speculate that such a fast rotation and high magnetic activity level could have been present on the Sun at a time where the growth of terrestrial planets was taking place. |
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