2000/07/07 by H. Korhonen, S. V. Berdyugina, Korhonen, H. +8
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #FOS: Physical sciences #Geophysics and Gravity Measurements #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0007088
10 pages, 7 figures, accepted for publication in A&A
arxiv created 2000/07/07 · openalex publication_date 2000/07/07 · arxiv updated 2016/08/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.