Four new HgMn stars: HD 18104, HD 30085, HD 32867, HD 53588

TL;DR

This study reports the discovery of four new HgMn stars identified through high-resolution spectroscopy, revealing significant elemental enhancements that reclassify these stars from normal to chemically peculiar HgMn types.

Contribution

The paper introduces four newly identified HgMn stars using high-resolution spectra and detailed spectral synthesis, expanding the known sample of chemically peculiar stars.

Findings

Four new HgMn stars identified through spectral analysis.

Detected significant Hg and Mn enhancements in these stars.

Reclassification of these stars from normal to HgMn chemically peculiar stars.

Abstract

We have detected four new HgMn stars, while monitoring a sample of apparently slowly rotating superficially normal bright late B and early A stars in the northern hemisphere. Important classification lines of Hg II and Mn II are found as conspicuous features in the high resolution SOPHIE spectra of these stars (R = 75000). Several lines of Hg II, Mn II and Fe II have been synthesized using model atmospheres and the spectrum synthesis code SYNSPEC48 including hyperfine structure of various isotopes when relevant. These synthetic spectra have been compared to high resolution high signal-to-noise observations of these stars in order to derive abundances of these key elements. The four stars are found to have distinct enhancements of Hg and Mn which show that these stars are not superficially normal B and A stars, but actually are new HgMn stars and should reclassified as such.