Distribution and evolution of starspots on the RS CVn binary II Pegasi in 2004

Yue Xiang, Sheng Hong Gu, A. Collier Cameron, J.R. Barnes

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5 Citations (Scopus)


We present Doppler images of RS CVn-type binary II Peg based on two data sets obtained in 2004 February and November. In order to improve signal-to-noise ratio and reliability,we apply least-squares deconvolution technique to calculate average profiles from 2032 photospheric absorption lines. Both of the resulting surface images show a wide latitude distribution of starspots. Most spots are concentrated at a high-latitude belt above 60° and a low-latitude belt near equator. The starspots evolved dramatically between two observing runs, which may indicate shorter time-scale evolution in this epoch, especially for low-latitude belt. There is no stable preferred active longitude that can be found in our images. We also find out a possible phenomenon that the intermediate-latitude spot migrated poleward and merged with the highlatitude spot to make it stronger, which may reveal a more complex behaviour of starspots on II Peg. A potential change of orbital ephemeris zero-point was detected. This may imply an orbital period change of II Peg like other active close binaries

Original languageEnglish
Article numberstt2345
Pages (from-to)2307-2316
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
Publication statusPublished - 1 Feb 2014


  • Activity-binaries
  • Close-stars
  • II Peg-starspots
  • Imaging-stars
  • Individual
  • stars


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