Open AccessA first detailed study of the colliding wind WR+O binary WR 30a
Author(s) -
Gosset E.,
Royer P.,
Rauw G.,
Manfroid J.,
Vreux J.M.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04755.x
Subject(s) - physics , astrophysics , amplitude , star (game theory) , circular orbit , orbital period , binary number , orbital motion , binary system , mass ratio , orbit (dynamics) , orbital inclination , phase (matter) , wolf–rayet star , stars , classical mechanics , optics , arithmetic , mathematics , angular momentum , engineering , quantum mechanics , aerospace engineering
We present a detailed, extensive investigation of the photometric and spectroscopic behaviour of WR 30a. This star is definitely a binary system with a period around 4.6 d. We propose the value . The identification of the components as WO4+O5((f)) indicates a massive evolved binary system; the O5 component is a main‐sequence or, more likely, a giant star. The radial velocities of the O star yield a circular orbit with an amplitude and a mass function of 0.013 . The spectrum of WR 30a exhibits strong profile variations of the broad emission lines that are phase‐locked with the orbital period. We report the detection of the orbital motion of the WO component with , but this should be confirmed by further observations. If correct, it implies a mass ratio . The star exhibits sinusoidal light variations of amplitude 0.024 mag peak‐to‐peak with the minimum of light occurring slightly after the conjunction with the O star in front. On the basis of the phase‐locked profile variations of the C iv λ 4658 blend in the spectrum of the WO, we conclude that a wind–wind collision phenomenon is present in the system. We discuss some possibilities for the geometry of the interaction region.