Browsing by Subject "BLUE STARS"
The spectroscopic orbit of HD 168112 A,B in NGC 6604: another massive binary target for interferometry
(MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2023-09-11) Putkuri, C.; Gamen, R.; Morrell, N.; Apellániz, J. M.; Arias, J.; Simón-Díaz, S.; Ferrero, G. A.; Rodríguez, C. N.; Sota, A.; Benvenuto, O. G.; Barbá, R. H.
We present the first spectroscopic orbit of the O-type double-lined star HD 168112 A,B. We analyse 101 high-resolution optical spectra identifying the absorption lines of both components. The orbital solution presents a relatively long period, P = 513.52 +/- 0.01 d, and a high eccentricity, e = 0.743 +/- 0.005. The binary system consists of two very similar stars of minimum masses of similar to 25 M-circle dot, effective temperatures of similar to 40 000 K, and surface gravities of similar to 3.7 dex. The system has a minimum semimajor axis a sin i similar to 1000 R-circle dot. We confirm that the A and B visual components identified via interferometry do correspond to the spectroscopic ones. We also analyse the underlying stellar groups using Gaia DR3 data and ground-based spectroscopy as part of the Villafranca project, determining that NGC 6604 is at a distance of 1942(-36)(+38) pc and giving spectral classifications for 23 massive stellar systems in Villafranca O-035 and the surrounding Ser OB2 association, for which we provide the most complete census of massive stars to date.