2015/12/01 by K. Bernhard, S. Huemmerich, S. Hümmerich +1 · 21 citations
Physics and Astronomy · #Asteroseismology #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Flare star #K-type main-sequence star #Light curve #Parallax #Rotation (mathematics) #Stars #Starspot #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1002/asna.201512214
published in Astronomische Nachrichten 336(10), 981-990 (Wiley) · 10 pages, 1 figure, 1 table
openalex publication_date 2015/12/01 · arxiv created 2015/12/12 · arxiv updated 2015/12/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract The magnetic chemically peculiar (CP2) stars of the upper main sequence are well‐suited for investigating the impact of magnetic fields on the surface layers of stars, which leads to abundance inhomogeneities (spots) resulting in photometric variability. The light changes are explained in terms of the oblique rotator model; the derived photometric periods thus correlate with the rotational periods of the stars. CP2 stars exhibiting this kind of variability are classified as α 2 Canum Venaticorum (ACV) variables. We have analysed around 3850000 individual photometric WASP measurements of magnetic chemically peculiar (CP2) stars and candidates selected from the catalogue of Ap, HgMn, and Am stars, with the ultimate goal of detecting new ACV variables. In total, we found 80 variables, from which 74 are reported here for the first time. The data allowed us to establish variability for 23 stars which had been reported as probably constant in the literature before. Light curve parameters were obtained for all stars by a least‐squares fit with the fundamental sine wave and its first harmonic. Because of the scarcity of Strömgren uvbyβ measurements and the lack of parallax measurements with an accuracy better than 20%, we are not able to give reliable astro‐physical parameters for the investigated objects. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)