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Analysis of MOST light curves of the active stars ɛ Eri AND κ Cet

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Abstract

We have analyzed light curves from the MOST satellite for the two active dwarfs ɛ Eri and κ Cet. Our maps of the stellar surface-temperature inhomogeneities were obtained with no a priori assumptions about the shape, configuration, and number of spots. We find variations of the surface-temperature inhomogeneities with time, also on time scales about equal to their rotation periods. We consider a model of a spotted star with two types of surface inhomogeneities—spots and related plage fields—and demonstrate that the best agreement between the theoretical and observed light curves is achieved for small ratios of the plage-field area to the area of cool spots. This conclusion indicates that long-term brightness variations of stars younger than the Sun are mainly due to variable spots on their surfaces, while the contribution from plage fields becomes more significant for older stars.

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Authors and Affiliations

  1. Institute of Astronomy, Russian Academy of Sciences, ul. Pyatnitskaya 48, Moscow, 119017, Russia

    I. S. Savanov

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  1. I. S. Savanov
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Original Russian Text © I.S. Savanov, 2009, published in Astronomicheskiĭ Zhurnal, 2009, Vol. 86, No. 10, pp. 1023–1029.

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Savanov, I.S. Analysis of MOST light curves of the active stars ɛ Eri AND κ Cet. Astron. Rep. 53, 950–956 (2009). https://doi.org/10.1134/S1063772909100060

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  • DOI: https://doi.org/10.1134/S1063772909100060

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