Comprehensive study of the magnetic stars HD 5797 and HD 40711 with large chromium and iron overabundances

TL;DR

This study investigates the magnetic and chemical peculiarities of stars HD 5797 and HD 40711, revealing significant overabundances of certain elements and a variable magnetic field, indicating advanced evolutionary stages.

Contribution

It provides detailed chemical abundance profiles and magnetic field measurements for two chemically peculiar stars, highlighting their evolutionary status and magnetic variability.

Findings

HD 5797's magnetic field varies sinusoidally between -100 and +1000 G.

Both stars show large overabundances of iron, chromium, and rare-earth elements.

Stars are estimated to be about 500 million years old, near the end of core hydrogen burning.

Abstract

We present the results of a comprehensive study of the chemically peculiar stars HD 5797 and HD 40711. The stars have the same effective temperature, Teff = 8900 K, and a similar chemical composition with large iron (+1.5 dex) and chromium (+3 dex) overabundances compared to the Sun. The overabundance of rare-earth elements typically reaches +3 dex. We have measured the magnetic field of HD 5797. The longitudinal field component Be has been found to vary sinusoidally between -100 and +1000 G with a period of 69 days. Our estimate of the evolutionary status of the stars suggests that HD 5797 and HD 40711, old objects with an age t \approx 5 \times 108 yr, are near the end of the core hydrogen burning phase.