A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Spot activity of II Peg
Tekijät: Hackman T, Mantere MJ, Jetsu L, Ilyin I, Kajatkari P, Kochukhov O, Lehtinen J, Lindborg M, Piskunov N, Tuominen I
Kustantaja: WILEY-BLACKWELL
Julkaisuvuosi: 2011
Lehti: Astronomical Notes / Astronomische Nachrichten
Tietokannassa oleva lehden nimi: ASTRONOMISCHE NACHRICHTEN
Lehden akronyymi: ASTRON NACHR
Numero sarjassa: 9-10
Vuosikerta: 332
Numero: 9-10
Aloitussivu: 859
Lopetussivu: 865
Sivujen määrä: 7
ISSN: 0004-6337
DOI: https://doi.org/10.1002/asna.201111616
Tiivistelmä
We have studied the long-term spot activity of the RS CVn star II Peg by means of Doppler imaging based on spectroscopy and time series analysis of photometry. We present 28 Doppler imaging temperature maps spanning the years 1994-2010, of which 14 were calculated for the present study. The longitudinal spot distribution, derived from the surface temperature maps, is compared with epochs of the light curve minima, derived from photometric observations. We detect a longitudinal drift in the major spot structure during 1995-2003. After this there is a clear decrease in the activity level and no clear drift can be seen. We conclude that the variations could be caused by a cyclic behaviour of the underlying magnetic dynamo. (C) 2011 WILEY-VCH Verlag GmbH& Co. KGaA, Weinheim
We have studied the long-term spot activity of the RS CVn star II Peg by means of Doppler imaging based on spectroscopy and time series analysis of photometry. We present 28 Doppler imaging temperature maps spanning the years 1994-2010, of which 14 were calculated for the present study. The longitudinal spot distribution, derived from the surface temperature maps, is compared with epochs of the light curve minima, derived from photometric observations. We detect a longitudinal drift in the major spot structure during 1995-2003. After this there is a clear decrease in the activity level and no clear drift can be seen. We conclude that the variations could be caused by a cyclic behaviour of the underlying magnetic dynamo. (C) 2011 WILEY-VCH Verlag GmbH& Co. KGaA, Weinheim
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