Project VeSElkA: results of abundance analysis for HD53929 and HD63975

TL;DR

This study investigates vertical element stratification in two HgMn stars, HD53929 and HD63975, revealing phosphorus stratification and confirming their classification through abundance analysis.

Contribution

First detection of phosphorus vertical stratification in HgMn stars using spectropolarimetric data and abundance analysis.

Findings

Phosphorus abundance increases towards the surface layers.

Both stars show strong manganese overabundance.

Evidence of vertical stratification of phosphorus in both stars.

Abstract

Project VeSElkA (Vertical Stratification of Element Abundances) has been initiated with the aim to detect and study the vertical stratification of element abundances in the atmosphere of chemically peculiar stars. Abundance stratification occurs in hydrodynamically stable stellar atmospheres due to the migration of the elements caused by atomic diffusion. Two HgMn stars, HD53929 and HD63975 were selected from the VeSElkA sample and analysed with the aim to detect some abundance peculiarities employing the ZEEMAN2 code. We present the results of abundance analysis of HD53929 and HD63975 observed recently with the spectropolarimeter ESPaDOnS at Canada-France-Hawaii Telescope. Evidence of phosphorus vertical stratification was detected in the atmosphere of these two stars. In both cases, phosphorus abundance increases strongly towards the superficial layers. The strong overabundance of Mn found in stellar atmosphere of both stars confirms that they are HgMn type stars.