HD172189: another step in furnishing one of the best laboratories known for asteroseismic studies

Abstract

HD172189 is a spectroscopic eclipsing binary system with a rapidly-rotating pulsating delta Scuti component. It is also a member of the open cluster IC4756. These combined characteristics make it an excellent laboratory for asteroseismic studies. To date, HD172189 has been analysed in detail photometrically but not spectroscopically. For this reason we have compiled a set of spectroscopic data to determine the absolute and atmospheric parameters of the components. We determined the radial velocities (RV) of both components using four different techniques. We disentangled the binary spectra using KOREL, and performed the first abundance analysis on both disentangled spectra. By combining the spectroscopic results and the photometric data, we obtained the component masses, 1.8 and 1.7 solar masses, and radii, 4.0 and 2.4 solar radii, for inclination i = 73.2 degrees, eccentricity e = 0.28, and orbital period 5.70198 days. Effective temperatures of 7600 K and 8100 K were also determined. The measured vsini are 78 and 74 km/s, respectively, giving rotational periods of 2.50 and 1.55 days for the components. The abundance analysis shows [Fe/H] = -0.28 for the primary (pulsating) star, consistent with observations of IC4756. We also present an assessment of the different analysis techniques used to obtain the RVs and the global parameters.

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References in corpus (4)

• The gamma Dor CoRoT target HD49434. I-Results from the ground-based campaign
• The non-LTE line formation of neutral carbon in late-type stars
• Pulsational frequencies of the eclipsing delta-Scuti star HD 172189
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Cited by in corpus (9)

• Catalogue and Properties of δ Scuti Stars in Binaries
• Observational $\Delta \nu$-$\bar{\rho }$ relation for $\delta$ Sct stars using eclipsing binaries and space photometry
• Eclipsing binary stars with a $\delta$ Scuti component
• Precise surface gravities of $\delta$ Scuti stars from asteroseismology
• Ground-based follow-up in relation to Kepler Asteroseismic Investigation
• Impact of gaps in the asteroseismic characterization of pulsating stars. I. On the efficiency of pre-whitening
• Stellar rotation, binarity, and lithium in the open cluster IC4756
• The envelope of the power spectra of over a thousand δScuti stars. The ${\bar{T}}_{eff}$-${\nu }_{max}$ scaling relation
• Constraining the properties of delta Scuti stars using spectroscopic eclipsing binary systems