V2324Cyg - an F-type star with fast wind

TL;DR

This study presents high-resolution spectroscopy of the variable star V2324Cyg, revealing detailed spectral features, wind velocities, and chemical abundances, challenging its previous classification as a post-AGB star.

Contribution

First detailed spectral analysis of V2324Cyg, providing new stellar parameters, wind velocities, and chemical abundance patterns that question its prior classification.

Findings

Identified over 200 absorption features including FeII, TiII, CrII, YII, BaII, and YII.

Measured wind velocities up to 450 km/s from Hα line.

Determined stellar parameters: Teff=7500K, log g=2.0, solar metallicity.

Abstract

For the first time high-resolution optical spectroscopy of the variable star V2324Cyg associated with the IR-source IRAS20572+4919 is made. More than 200 absorption features (mostly FeII, TiII, CrII, YII, BaII, and YII) are identified within the wavelength interval 4549-7880AA. The spectral type and rotation velocity of the star are found to be F0III and Vsini=69km/s, respectively. HI and NaID lines have complex PCyg-type profiles with an emission component. Neither systematic trend of radial velocity Vr with line depth Ro nor temporal variability of Vr have been found. We determined the average heliocentric radial velocity Vr=-16.8\pm 0.6km/s. The radial velocities inferred from the cores of the absorption components of the H$\beta$ and NaI wind lines vary from -140 to -225km/s (and the expansion velocities of the corresponding layers, from about 120 to 210km/s). The maximum expansion velocity is found for the blue component of the split H$\alpha$ absorption: 450km/s for December 12, 1995. The model atmospheres method is used to determine the star's parameters: Teff=7500K, log g=2.0, $\xi_t$=6.0km/s, and metallicity, which is equal to the solar value. The main peculiarity of the chemical abundances pattern is the overabundance of lithium and sodium. The results cast some doubt on the classification of V2324Cyg as a post-AGB star.