Analyses of multi-epoch , high-resolution ( R \sim 50.000 ) optical spectra of the O-type star HD 152246 ( O9 IV according to the most recent classification ) , complemented by a limited number of earlier published radial velocities , led to the finding that the object is a hierarchical triple system , where a close inner pair ( Ba–Bb ) with a slightly eccentric orbit ( e = 0.11 ) and a period of 6 \aas@@fstack { d } 0049 revolves in a 470-day highly eccentric orbit ( e = 0.865 ) with another massive and brighter component A .
The mass ratio of the inner system must be low since we were unable to find any traces of the secondary spectrum .
The mass ratio A/ ( Ba+Bb ) is 0.89 .
The outer system has recently been resolved using long-baseline interferometry on three occasions .
The interferometry confirms the spectroscopic results and specifies elements of the system .
Our orbital solutions , including the combined radial-velocity and interferometric solution indicate an orbital inclination of the outer orbit of 112 ^ { \circ } and stellar masses of 20.4 and 22.8 M _ { \odot } .
We also disentangled the spectra of components A and Ba and compare them to synthetic spectra from two independent programmes , TLUSTY and FASTWIND .
In either case , the fit was not satisfactory and we postpone a better determination of the system properties for a future study , after obtaining observations during the periastron passage of the outer orbit ( the nearest chance being March 2015 ) .
For the moment , we can only conclude that component A is an O9 IV star with v sin i = 210 \pm 10 km s ^ { -1 } and effective temperature of 33000 \pm 500 K , while component Ba is an O9 V object with v sin i = 65 \pm 3 km s ^ { -1 } and T _ { eff } = 33600 \pm 600 .