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

Context: Recent attention has been directed to abundance variations amongvery young stars.  Aims: To perform a detailed abundance study of the Herbig Ae star HD 101412,taking advantage of its unusually sharp spectral lines.  Methods: High-resolution spectra are measured for accurate wavelengths andequivalent widths. Balmer-line fits and ionization equlibria give a relationbetween Teff, and log(g). Abundance anomalies and uncertain reddening precludethe use of spectral type or photometry to fix Teff. Excitation temperatures areused to break the degeneracy between Teff and log(g).  Results: Strong lines are subject to an anomalous saturation that cannot beremoved by assuming a low microturbulence. By restricting the analysis to weak(<= 20 m[A]) lines, we find consistent results for neutral and ionized species,based on a model with Teff = 8300K, and log(g)=3.8. The photosphere is depletedin the most refractory elements, while volatiles are normal or, in the case ofnitrogen, overabundant with respect to the sun. The anomalies are unlike thoseof Ap or Am stars.  Conclusions: We suggest the anomalous saturation of strong lines arises fromheating of the upper atmospheric layers by infalling material from a disk. Theoverall abundance pattern may be related to those found for the Lambda Boostars, though the depletions of the refractory elements are milder, more likethose of Vega. However, the intermediate volatile zinc is depleted, precludinga straightforward interpretation of the abundance pattern in terms of gas-grainseparation.

Abundances in the Herbig Ae star HD 101412: Abundance anomalies; Lambda Boo-Vega characteristics?