Study of FK Comae Berenices. II. Spot evolution from 1994 to 1997
Abstract
We present new surface (Doppler) images of the late-type single giant FK Com for June-July 1996, July-August 1996, April 1997 and June 1997. These images are compared with the previously published images from 1994 and 1995. The consecutive maps are cross-correlated to see the possible migration of the spots and the effects of differential rotation. The cross-correlation confirms an average longitudinal spot migration of 0.22+/-0.03 in phase within a year. This movement is probably an artifact caused by a difference between the accepted rotation period and the real photometric period for these years. If this is true, then the photometric rotation period for these years is 2.4037+/-0.0005 days. Measurements from these four years and six maps limit the surface differential rotation to alpha=0.0001+/-0.0002, where alpha is the difference between polar and equatorial angular velocities relative to the equatorial angular velocity.
Cite
@article{arxiv.astro-ph/0007088,
title = {Study of FK Comae Berenices. II. Spot evolution from 1994 to 1997},
author = {H. Korhonen and S. V. Berdyugina and T. Hackman and K. G. Strassmeier and I. Tuominen},
journal= {arXiv preprint arXiv:astro-ph/0007088},
year = {2016}
}
Comments
10 pages, 7 figures, accepted for publication in A&A