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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present updated magnetic field maps of the chemically peculiar B9p star$\alpha^2$ CVn created using a series of time resolved observations obtainedusing the high resolution spectropolarimeters ESPaDOnS and Narval. We comparethese new magnetic field maps with the original magnetic Doppler imaging mapsbased on spectra recorded with the MuSiCoS spectropolarimeter and taken adecade earlier. These new maps are inferred from line profiles in all fourStokes parameters using the magnetic Doppler imaging code INVERS10. With theaddition of new lines exhibiting Stokes $IQUV$ signatures we have a uniqueinsight into how the derived magnetic surface structure may be affected by theatomic lines chosen for inversion. We report new magnetic maps of $\alpha^2$CVn created using strong iron lines (directly comparable to the publishedMuSiCoS maps), weak iron lines and chromium lines, all of which yield amagnetic field structure roughly consistent with that obtained previously.  We then derive an updated magnetic structure map for $\alpha^2$ CVn based onthe complete sample of Fe and Cr lines, which we believe to produce a morerepresentative model of the magnetic topology of $\alpha^2$ CVn. In agreementwith the previous mapping, this new updated magnetic map shows a dipolar-likefield which has complex sub-structure which cannot be explained by a simple loworder multipolar geometry. Our new maps show that regardless of the atomic lineor species choice, the reconstructed magnetic field is consistent with thatpublished previously, suggesting that the reconstructed field is a realisticrepresentation of the magnetic field of $\alpha^2$ CVn. $\alpha^2$ CVn is thefirst Ap star for which multiple, high resolution magnetic maps have beenderived, providing important observational evidence for the stability of boththe large and small-scale magnetic field.

Stokes $IQUV$ Magnetic Doppler Imaging of Ap stars II: Next Generation Magnetic Doppler Imaging of $\alpha^2$ CVn