Ref: SCART-2021-0161

High-resolution spectroscopy of “hump and spike” stars

Trust, O. ; Jurua, E. ; De Cat, P. ; Joshi, S.

in press to Proceedings of the 6th East African Astronomical Society Workshop (2022)

Abstract: We used data collected with the High Efficiency and Resolution Mercator Echelle Spectrograph (HERMES). We determined the spectral type of these stars and obtained the atmospheric stellar parameters such as effective temperatures, surface gravities, projected rotational, microturbulent and radial velocities. We also performed a detailed individual chemical abundance analysis for each target. We confirmed KIC 3459226 (kA2hF0mF3) and KIC 6266219 (kA3hA7mF1) as Am stars, KIC 9349245 as a marginal Am star, while KIC 4567097, KIC 4818496, KIC 5524045, KIC 5650229, KIC 7667560, and KIC 9272082 are non-Am stars. Using the MESA evolution code, the evaluation of the transport processes indicates that radiative diffusion, combined with turbulent mixing, thermohaline convection, and slow to moderate rotation can account for most of the chemical peculiarities found in Am stars. The differences in abundances suggest that there are other mechanisms at work, which are currently unknown, that contribute to the chemical anomalies identified in Am stars.

The record appears in these collections:
Royal Observatory of Belgium > Astronomy & Astrophysics
Science Articles > Non-refereed Articles

 Record created 2021-12-21, last modified 2021-12-21

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