English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Since the discovery of the spectral peculiarities of their prototype alpha2Canum Venaticorum in 1897, the so-called ACV variables, which are comprised ofseveral groups of chemically peculiar stars of the upper main sequence, havebeen the target of numerous photometric and spectroscopic studies. Especiallyfor the brighter ACV variables, continuous observations over about a centuryare available, which are important to study long-term effects such as periodchanges or magnetic cycles in these objects. The present work presents ananalysis of 165 Ap/CP2 and He-weak/CP4 stars using light curves obtained by theSolar Mass Ejection Imager (SMEI) between the years 2003 and 2011. These datafill an important gap in observations for bright ACV variables between theHipparcos and TESS satellite missions. Using specifically tailored datatreatment and period search approaches, we find variability in the accuracylimit of the employed data in 84 objects. The derived periods are in excellentagreement with the literature; for one star, the here presented solutionrepresents the first published period. We discuss the apparently constant starsand the corresponding level of non-variability. From an investigation of ourtarget star sample in the Hertzsprung-Russell diagram, we deduce ages between100 Myr and 1 Gyr for the majority of our sample stars. Our results supportthat the variable CP2/4 stars are in a more advanced evolutionary state andthat He and Si peculiarities, preferentially found in the hotter, and thus moremassive, CP stars, produce larger spots or spots of higher contrast.

Magnetic chemically peculiar stars investigated by the Solar Mass Ejection Imager