p Velorum and Stellar Evolution

A new age determination for γ Velorum from binary stellar evolution models

We derive a new age for the γ Velorum binary by comparing recent observations to our set of binary models. We find that it is very unlikely the stars have not interacted, which implies that previous estimates of the age from single-star models of 3.5 ± 0.4 Myrs are incorrect. We prefer an older age of 5.5 ± 1 Myrs that agrees with the age of other lower mass stars in the Vela OB association. We...

The nearby eclipsing stellar system δ Velorum IV . Differential

Context. The stellar system δVel contains the brightest eclipsing binary in the southern sky (δVel A), and a nearby third star located ≈ 0.6′′ away (δVel B). The proximity of δVel B (usable as a reference) makes it a particularly well-suited target to detect the astrometric displacement of the center of light of the eclipsing pair. Aims. We obtained NACO astrometric observations with two goals:...

Stellar Structure and Evolution

THE BANANA PROJECT. V. MISALIGNED AND PRECESSING STELLAR ROTATION AXES IN CV VELORUM Citation

As part of the BANANA project (Binaries Are Not Always Neatly Aligned), we have found that the eclipsing binary CV Velorum has misaligned rotation axes. Based on our analysis of the Rossiter-McLaughlin effect, we find sky-projected spin-orbit angles of βp = −52± 6◦ and βs = 3± 7◦ for the primary and secondary stars (B2.5V + B2.5V, P = 6.9 d). We combine this information with several measurement...

The stellar association around Gamma Velorum and its relationship with Vela OB2

We present the results of a photometric BV I survey of 0.9 square degrees around the Wolf-Rayet binary γ Vel and its early-type common proper motion companion γ Vel (together referred to as the γ Vel system). Several hundred pre-main-sequence (PMS) stars are identified and the youth of a subset of these is spectroscopically confirmed by the presence of lithium in their atmospheres, Hα emission ...