Hostname: page-component-77c89778f8-vsgnj Total loading time: 0 Render date: 2024-07-22T06:27:59.283Z Has data issue: false hasContentIssue false

Periodic Variability on Time-scales of Decades to Centuries in Magnetic Ap Stars: Challenges and Strategies

Published online by Cambridge University Press:  29 August 2019

G. Mathys*
Joint ALMA Observatory & European Southern Observatory, Santiago, Chile email:
Rights & Permissions [Opens in a new window]


Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Recent studies have revealed the existence of a significant population of Ap stars with extremely long rotation periods, and the frequent occurrence of Ap stars in wide binaries. Those results represent new constraints on the understanding of the origin and evolution of Ap stars, and (by extension) of all upper-main-sequence stars. Current knowledge of Ap stars with the longest rotation and orbital periods remains incomplete, on the one hand because in many cases the periods of interest are longer than the time-spans over which relevant observations have been obtained, and on the other hand because some important subsets of Ap stars have been omitted from the studies that have been carried out until now. Additional observations over time-scales of decades to centuries are needed to complement the current incomplete picture. Securing them with the required accuracy and time coverage, and ensuring that their full exploitation will ultimately be possible, represents a unique challenge in time-domain astronomy.

Contributed Papers
© International Astronomical Union 2019 


Belopolsky, A. 1913, AN, 195, 159Google Scholar
Bailey, J. D., Grunhut, J., & Landstreet, J. D. 2015, A&A, 575, A115Google Scholar
Braithwaite, J., & Spruit, H. C. 2017, Royal Society Open Science, 16027110.1098/rsos.160271CrossRefGoogle Scholar
Bychkov, V. D., Bychkova, L. V., & Madej, J. 2016, MNRAS, 455, 2567CrossRefGoogle Scholar
Carrier, F., North, P., Udry, S., & Babel, J. 2002, A&A, 394, 151Google Scholar
Mathys, G. 2004, in: Maeder, A. & Eenens, P. (eds.), Stellar Rotation, Proc. IAUS 215, (ASPCS), p. 270Google Scholar
Mathys, G. 2015, in: Balega, Y. Y., Romanyuk, I. I., & Kudryavtsev, D. O., Physics and Evolution of Magnetic and Related Stars, (ASPCS), 494, p. 3Google Scholar
Mathys, G. 2017, A&A, 601, A14Google Scholar
Preston, G. W., & Wolff, S. C. 1970, ApJ, 160, 1071CrossRefGoogle Scholar
Scholz, G. 1983, Ap&SS, 94, 159Google Scholar
Wolff, S. C. 1975, ApJ, 202, 127CrossRefGoogle Scholar
Wolff, S. C., & Morrison, N. D. 1973, PASP, 85, 141CrossRefGoogle Scholar