Open AccessThe nearest star of spectral type O3: a component of the multiple system HD 150136
Author(s) -
Niemela V. S.,
Gamen R. C.
Publication year - 2005
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 - 10.1111/j.1365-2966.2004.08513.x
Subject(s) - physics , radial velocity , orbital motion , astrophysics , orbital elements , binary number , spectral line , orbital inclination , binary star , orbital period , binary system , orbit (dynamics) , component (thermodynamics) , astronomy , stars , classical mechanics , angular momentum , arithmetic , mathematics , engineering , aerospace engineering , thermodynamics
From radial velocities determined in high signal‐to‐noise digital spectra, we report the discovery that the brightest component of the binary system HD 150136 is of spectral type O3. We also present the first double‐lined orbital solution for this binary. Our radial velocities confirm the previously published spectroscopic orbital period of 2.6 d. He ii absorptions appear double at quadratures, but single lines of N v and N iv visible in our spectra define a radial velocity orbit of higher semi‐amplitude for the primary component than do the He ii lines. From our orbital analysis, we obtain minimum masses for the binary components of 27 and 18 M ⊙ . The neutral He absorptions apparently do not follow the orbital motion of any of the binary components, thus they most probably arise in a third star in the system.