binaries : general; stars : early-type; stars : fundamental parameters; stars : individual : CPD 59 degrees 2636; open clusters and associations : individual : Trumpler 16; X-rays : stars
Abstract :
[en] High-resolution optical spectroscopy of CPD -59degrees2636, one of the O-type stars in the open cluster Trumpler 16 in the Carina Nebula, reveals this object to be a multiple system displaying triple lines which we label as components A, B and C of spectral types O7 V, O8 V and O9 V, respectively. From our radial velocity measurements we find that the components A and B form a close binary with a period of 3.6284 d, and we obtain the first circular radial velocity orbit for this system with semi-amplitudes of 184 and 192 km s(-1), leading to minimum masses of 10.1 and 9.7 M-.. We find that the component C is a single lined binary with a period of 5.034 d and semi-amplitude of 48 km s(-1). We also analyse the X-ray radiation from CPD -59degrees2636, finding neither appreciable overluminosity nor phase-related X-ray flux variations.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Albacete Colombo, J. F.
Morrell, N. I.
Rauw, Grégor ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE)
Corcoran, M. F.
Niemela, V. S.
Sana, H.
Language :
English
Title :
Optical spectroscopy of X-Mega targets - IV. CPD-59 degrees 2636: a new O-type multiple system in the Carina Nebula