High resolution study of the young quadruple system AOVel with an eclipsing BpSi primary

GONZÁLEZ, J. F.; NESVACIL, N.; HUBRIG, S.

Aveiro, Portugal

Conferencia; Precision Spectroscopy in Astrophysics; 2006

ESO - Univ. Lisboa - Univ. Aveiro

During last year’s analysis of FEROS spectra, we discovered that the triple system AO Vel with an eclipsing BpSi primary is in fact a remarkable quadruple system with ZAMS and PMS companions. Our recently obtained three UVES spectra of the AO Vel system disclose that the components of the eclipsing primary show variable Si and He line profiles and the components of the secondary, less massive system are both HgMn stars exhibiting strong overabundance at least of the elements Hg, Mn, Y, and Pt. No other system consisting of such an amazing combination of different types of chemically peculiar stars is known until now. Our current high spectral resolution study of this quadruple system aims at the determination of the element abundances in the atmospheres of all four companions as well as their distribution over the stellar surface. Such a study is important for our understanding of the origin of chemical anomalies at a very young age as well as for the development of stellar evolution models.