Volume 474, Number 1, October IV 2007
|Page(s)||165 - 168|
|Section||Stellar structure and evolution|
|Published online||28 August 2007|
Anti-solar differential rotation on the active K-giant Geminorum
Konkoly Observatory, 1525 Budapest, PO Box 67, Hungary e-mail: firstname.lastname@example.org
2 Astrophysical Institute Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany e-mail: [jbartus;kstrassmeier]@aip.de
3 Eötvös University, Department of Astronomy, 1518 Budapest, PO Box 32, Hungary e-mail: email@example.com
4 Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 18000 Prague 8, Czech Republic e-mail: firstname.lastname@example.org
5 Astronomical Institute, Academy of Sciences of the Czech Republic, v. v. i., Fričova 298, 25165 Ondřejov, Czech Republic
Accepted: 21 July 2007
The active K1 giant σ Gem and its differential surface rotation is revisited. We refine our previous inconclusive result by recovering the spot migration pattern of this long-period RS CVn-type binary through application of the technique of “average cross-correlation of contiguous Doppler images” to a set of six Doppler images from 3.6 consecutive rotation cycles. We find an anti-solar differential rotation law with a shear of -0.022±0.006. We also find evidence of a poleward migration trend of spots with an average velocity of ≈300 m s-1.
Key words: stars: activity / stars: imaging / stars: late-type / stars: starspots / stars: individual: σ Geminorum
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.