Is beryllium ultra-depletion in solar-type stars linked to the presence of a white dwarf companion?

Abstract

Abundance studies of solar-type stars revealed a small fraction of objects with extreme depletion of beryllium. We investigate the possible link between the beryllium depletion and the presence of companions. The classical methods (radial velocity, astrometry, imaging) used to search for binary companions were exploited. We also performed a chemical analysis to identify binaries by the alteration in abundances that is produced by the accretion of material lost by a former evolved companion. We found that all the four previously investigated stars that were found to be ultra--depleted in Be are binaries. In two cases the companion is a white dwarf, and in the other two cases the companion might be a white dwarf or a main-sequence star. One new barium star was identified. We speculate that the interaction with the white dwarf progenitor caused an alteration in the abundance pattern of the star, which resulted in severe beryllium depletion. Possible mechanisms such as thermohaline mixing, episodic accretion, and rotational mixing are discussed. We also briefly discuss predictions for validating this scenario

Astronomy & Astrophysics, in press, 6 pages, 3 figures

References in corpus (11)

• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• A survey of the high order multiplicity of nearby solar-type binary stars with Robo-AO
• The Palomar/Keck Adaptive Optics Survey of Young Solar Analogs: Evidence for a Universal Companion Mass Function
• Properties of planets in binary systems. The role of binary separation
• Lithium depletion and the rotational history of exoplanet host stars
• Enhanced production of barium in low-mass stars: evidence from open clusters
• Thermohaline mixing and gravitational settling in carbon-enhanced metal-poor stars
• Speckle interferometry at SOAR in 2014
• Astrometric Orbits for Hipparcos Stochastic Binaries
• HIP 10725: The First Solar Twin/Analogue Field Blue Straggler
• Spectroscopic Study on the Beryllium Abundances of Red Giant Stars

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• HIP 10725: The First Solar Twin/Analogue Field Blue Straggler
• A new white dwarf companion to the $\Delta \mu$ star GJ 3346
• Investigating three Sirius-like systems with SPHERE
• Project 1640 Observations of the White Dwarf HD 114174 B
• Spectroscopic determination of C, N, and O abundances of solar-analog stars based on the lines of hydride molecules
• Beryllium: The smoking gun of a rejuvenated star