We present a time-series Doppler imaging study of the K-subgiant component in the RS CVn-type binary system IL Hya (P orb=12.905 d). From re-processing the unique long-term spectroscopic dataset of 70 days taken in 1996/97, we perform a thorough cross-correlation analysis to derive surface differential rotation. As a result we get solar-type differential rotation with a shear value alpha of 0.05, in agreement with preliminary suggestions from previous attempts. A possible surface pattern of meridional circulation is also detected.
@article{arxiv.1309.1378,
title = {Surface differential rotation of IL Hya from time-series Doppler images},
author = {Zsolt Kővári and Levente Kriskovics and Katalin Oláh and Krisztián Vida and János Bartus and Klaus G. Strassmeier and Michael Weber},
journal= {arXiv preprint arXiv:1309.1378},
year = {2015}
}
Comments
2 pages, 2 figures, to be appeared in "Magnetic Fields Throughout the Stellar Evolution", Proc. IAU Symp. 302