Multidataset analysis of a nearby eclipsing binary system delta Velorum
Authors:
T. Pribulla et al.
Image & caption:
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Image caption::
Synthetic image of the eclipsing pair in linear scale close to the secondary eclipse.
Description:
The nearby multiple system delta Velorum contains a widely detached
eclipsing binary and a third component. The system offers the opportunity
to determine the set of fundamental parameters (masses, luminosities, and
radii) of three coeval stars with sufficient precision to test models of
stellar evolution. The system is studied by combining several
complementary datasets: extensive high-resolution spectroscopy, the SMEI
satellite light curve, VLTI NIR interferometry and
AO VLT observations.
The observations show that components of the eclipsing pair rotate at
about two-thirds of the break-up velocity, which excludes any chemical
peculiarity and results in a non-uniform surface brightness. Although the
inner orbit is eccentric, no apsidal motion is seen during the SMEI
photometric observations. For the inner orbit, the orbital parameters are:
eccentricity e = 0.290, longitude of the periastron passage 109 deg, and
inclination 89.0 deg. The component masses of MAa = 2.53(11) solar masses,
MAb = 2.37(10) solar masses, and MB about 1.5 solar masses combined with
the inferred radii of the Aa and Ab components indicate that the eclipsing
pair has already left the main sequence and that the estimated age of the
system is about 400 Myr.
Combination of the spectroscopic and interferometric orbit result in a
parallax of 39.8(4) mas for the system, in satisfactory agreement with the
Hipparcos value 40.5(4).
Reference:
Pribulla, T., Mérand, A., Kervella, P. et al., Astronomy & Astrophysics 528, 21 (2011); Mérand, A., Kervella, P., Pribulla, T. et al., Astronomy & Astrophysics 532, 50 (2011)
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