Poster - Splinter Stars

Wednesday, 15 September 2021, 17:55   (virtual Stars)

New "Pseudo-Rotating" Stellar Atmospheres

Gabriel Szász
Masaryk University

When it comes to model atmospheres, rotation effects are mostly neglected, and, at best, the rotational broadening correction is applied to a non-rotating synthetic spectrum. However, this approximation does not work for fast rotators (v_eq > 200 km/s), where the effect given by von Zeipel's Theorem starts to be prominent. The need for this correction is significant for the main sequence stars hotter than F7. We currently work on a new model atmosphere grid for A- and B-type stars. The parameter space is extended for equatorial velocity and inclination to provide synthetic spectra and colors corrected for von Zeipel's Theorem. Individual synthetic spectra are based on 1-dimensional plane-parallel results of the ATLAS12 code; thus, the new grid provides only a stationary "pseudo-rotating" model atmosphere. Despite this limitation, as we conclude in this contribution, the method used in our project still represents a significant improvement over the conventional approach.