Multiperiodicity, modulations and flip-flops in variable star light curves II. Analysis of II Peg photometry during 1979-2010

摘要: According to earlier Doppler images of the magnetically active primary giant component RS CVn binary II Peg, surface star was dominated by one single longitude that clearly drifting in rotational frame system during 1994-2002; later imaging for 2004-2010, however, showed decreased and chaotic spot activity, with no signs drift pattern. Here we set out investigate from a more extensive photometric dataset whether such is persistent phenomenon, which case it could be due either an azimuthal dynamo wave or indication orbital synchronization still being incomplete. We analyse datasets using Carrier Fit method (hereafter CF), especially suitable analyzing time series fast clocking frequency (such as rotation star) modulated slower process stellar activity cycle). combine all collected data into set, analyze CF method. As result, confirm results having been spotted region almost through entire existence persistent, nearly linear drift. Disruptions trend complicated phase behavior are also seen, but period analysis reveals rather stable periodicity P(spot)=6.71054d plus/minus 0.00005d. After removed data, identify several abrupt jumps, three analyzed detail These jumps closely resemble what called flip-flop event, new configurations do not, most cases, persist longer than few months.