Unseen companions of V Hya inferred from periodic ejections

Abstract

A recent study using $Hubble$ $Space$ $Telescope$ observations found periodic, high-speed, collimated ejections (or "bullets") from the star V Hya. The authors of that study proposed a model associating these bullets with the periastron passage of an unseen, substellar companion in an eccentric orbit and with an orbital period of $\sim 8$ yrs. Here we propose that V Hya is part of a triple system, with a substellar companion having an orbital period of $\sim 8$ yrs, and a tertiary object on a much wider orbit. In this model, the more distant object causes high-eccentricity excitations on the substellar companion's orbit via the Eccentric Kozai-Lidov mechanism. These eccentricities can reach such high values that they lead to Roche-lobe crossing, producing the observed bullet ejections via a strongly enhanced accretion episode. For example, we find that a ballistic bullet ejection mechanism can be produced by a brown-dwarf-mass companion, while magnetically driven outflows are consistent with a Jovian-mass companion. Finally, we suggest that the distant companion may reside at few a hundred AU on an eccentric orbit.

Accepted to MNRAS. 10 pages, 6 figures, 1 table

References in corpus (12)

• Tertiary companions to close spectroscopic binaries
• Contact Binaries with Additional Components.I. The Extant Data
• A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
• Mergers and Obliquities in Stellar Triples
• Steady-state planet migration by the Kozai-Lidov mechanism in stellar binaries
• Comparative statistics and origin of triple and quadruple stars
• Chaos in the Test Particle Eccentric Kozai-Lidov Mechanism
• The triple evolution dynamical instability: Stellar collisions in the field and the formation of exotic binaries
• Retired A Stars and Their Companions II: Jovian planets orbiting kappa Coronae Borealis and HD167042
• Secular Evolution Of Binaries Near Massive Black Holes: Formation of compact binaries, merger/collision products and G2-like objects
• The Pan-Pacific Planet Search. II. Confirmation of a two-planet system around HD 121056
• Roche-lobe overflow in eccentric planet-star systems

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