The first orbital solution for the massive colliding-wind binary HD 93162 (=WR 25)

GAMEN, R.; GOSSET, E.; MORRELL, N.; NIEMELA, V. S.; SANA, H.; NAZÉ, Y.; BARBÁ, R.; SOLIVELLA, G. R.

ASTRONOMY AND ASTROPHYSICS

Año: 2006 vol. 460 p. 777 - 782

0004-6361

Context: .Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD 93162 (= WR 25), this object has been predicted to be a colliding-wind binary system. However, radial-velocity variations that would prove the suspected binary nature have yet to be found.Aims: .We spectroscopically monitored this object to investigate its possible variability to addressthis discordance.Methods: .We compiled the largest available radial-velocity data set for this star to look for variations that might be due to binary motion. We derived radial velocities from spectroscopic data acquired mainly between 1994 and 2006, and searched these radial velocities for periodicities using different numerical methods.Results: .For the first time, periodic radial-velocity variations are detected.Our analysis definitively shows that the Wolf-Rayet star WR 25 is an eccentric binary systemwith a probable period of about 208 days.