Rodríguez-Gil, P.; Santander-García, M.; Knigge, C.; Corradi, R. L. M.; Gänsicke, B. T.; Barlow, M. J.; Drake, J. J.; Drew, J.; Miszalski, B.; Napiwotzki, R.; Steeghs, D.; Wesson, R.; Zijlstra, A. A.; Jones, D.; Liimets, T.; Muñoz-Darias, T.; Pyrzas, S.; Rubio-Díez, M. M.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society: Letters, Volume 407, Issue 1, pp. L21-L25.
Description
We present time-resolved optical spectroscopy of V458 Vulpeculae (Nova
Vul 2007 No. 1) spread over a period of 15 months starting 301d after
its discovery. Our data reveal radial-velocity variations in the HeII
λ5412 and HeII λ4686 emission lines. A period analysis of
the radial-velocity curves resulted in a period of 98.09647 +/-
0.00025min (0.06812255 +/- 0.00000017d) which we identify with the
orbital period of the binary system. V458 Vul is therefore the planetary
nebula central binary star with the shortest period known. We explore
the possibility of the system being composed of a relatively massive
white dwarf (M1 >~ 1.0 Msolar) accreting matter
from a post-asymptotic giant branch star which produced the planetary
nebula observed. In this scenario, the central binary system therefore
underwent two common-envelope episodes. A combination of previous
photoionization modelling of the nebular spectra, post-asymptotic giant
branch evolutionary tracks and the orbital period favour a mass of
M2 ~ 0.6 Msolar for the donor star. Therefore, the
total mass of the system may exceed the Chandrasekhar mass, which makes
V458 Vul a Type Ia supernova progenitor candidate.
Related projects
This project has three major objectives: 1) To determine the physico-chemical characteristics of bipolar planetary nebulae and symbiotic nebulae, to help understanding the origin of bipolarity and to test theoretical models, mainly models with binary central stars, aimed at explaining the observed morphology and kinematics. 2) To study the low
The study of binary stars is essential to stellar astrophysics. A large number of stars form and evolve within binary systems. Therefore, their study is fundamental to understand stellar and galactic evolution. Particularly relevant is that binary systems are still the best source of precise stellar mass and radius measurements. Research lines
