The eccentric short-period orbit of the supergiant fast X-ray transient HD 74194 (=LM Vel)

DOI: 
10.1051/0004-6361/201527140
Publication date: 
01/11/2015
Main author: 
Gamen R.
IAA authors: 
Sota A.;Alfaro E.J.
Authors: 
Gamen R., Barba R.H., Walborn N.R., Morrell N.I., Arias J.I., Maiz Apellaniz J., Sota A., Alfaro E.J.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
583
Pages: 
Number: 
L4
Abstract: 
We present the first orbital solution for the O-type supergiant star HD 74194, which is the optical counterpart of the supergiant fast X-ray transient IGR J08408-4503. Methods. We measured the radial velocities in the optical spectrum of HD 74194, and we determined the orbital solution for the first time. We also analysed the complex Hα profile. Results. HD 74194 is a binary system composed of an O-type supergiant and a compact object in a short-period (P = 9.5436 ± 0.0002 d) and high-eccentricity (e = 0.63 ± 0.03) orbit. The equivalent width of the Hα line is not modulated entirely with the orbital period, but seems to vary in a superorbital period (P = 285 ± 10 d) nearly 30 times longer than the orbital one. © 2015 ESO.
Database: 
WOK
SCOPUS
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2015A&A...583L...4G/abstract
ADS Bibcode: 
2015A&A...583L...4G
Keywords: 
Binaries: spectroscopic; Stars: early-type; Stars: individual: HD 74194