Starspot activity on the RS CVn-type binary II Pegasi during 1999-2001
National Astronomical Observatories/Yunnan Observatory, Joint Laboratory for Optical Astronomy, Chinese Academy of Sciences, Kunming, PR China
Corresponding author: S.-H. Gu, email@example.com
Accepted: 6 May 2003
By means of Doppler imaging, new high-resolution spectroscopic observations of II Peg, carried out in three observing seasons from 1999 to 2001, were analyzed. The lines FeI6430.844 Å and CaI6439.075 Å were chosen as map lines, and three surface maps of II Peg were obtained. The results demonstrate that the main features of these surface maps are high-latitude active regions around 60° and no polar cap is seen in the maps. The surface patterns of II Peg show large changes, the largest scale active regions appear in July-Aug. 1999 and then they become small and separated in Feb. 2000. The active longitude switches to another hemisphere in Nov.-Dec. 2001 from the one in Feb. 2000. Such spot evolution is not consistent with the activity cycle derived previously.
Key words: stars: late-type / stars: activity / stars: imaging / stars: starspots / stars: individual: II Peg
© ESO, 2003