The magnetic field of the chemically peculiar star V352Peg

TL;DR

This study presents spectropolarimetric observations and magnetic field modeling of the chemically peculiar Bp star V352Peg, revealing a strong, mainly dipolar magnetic field and surface chemical spots.

Contribution

First detailed magnetic field mapping of V352Peg using Zeeman-Doppler Imaging and spectropolarimetry, providing insights into its magnetic geometry and surface chemical distribution.

Findings

Magnetic field is mainly dipolar and poloidal with ~9 kG strength.

Detected chemical spots on the stellar surface.

Magnetic axis nearly perpendicular to the rotation axis.

Abstract

We present a spectropolarimetric analysis of the hot star V352Peg. We have acquired 18 spectropolarimetric observations of the star with ESPaDOnS at the CFHT between 2018 and 2019 and completed our dataset with one archival ESPaDOnS measurement obtained in 2011. Our analysis of the spectra shows that the star is on the main sequence and chemically peculiar, i.e. it is a Bp star, with overabundances of iron peak elements (Ti, Cr and Fe) and underabundance of He and O. Through a Least-Square Deconvolution of each spectrum, we extracted the mean Zeeman signature and mean line profile of thousands of spectral lines and detected a magnetic field in V352Peg. By modelling the Stokes I and V profiles and using the Oblique Rotator Model, we determined the geometrical configuration of V352Peg. We also performed Zeeman-Doppler Imaging (ZDI) to provide a more detailed characterization of the magnetic field of V352Peg and its surface chemical distributions. We find a magnetic field that is mainly dipolar, dominantly poloidal, and largely non-axisymmetric with a dipole field strength of $\sim$9 kG and a magnetic axis almost perpendicular to the rotation axis. The strong variability of Stokes I profiles also suggests the presence of chemical spots at the stellar surface.