paper

Study of Eclipsing Binary and Multiple Systems in OB Associations V: MQ Cen in Crux OB1

arXiv:1906.01913 · doi:10.1007/s10509-019-3650-9

Abstract

The early-type massive binary MQ Cen (P $_{or b}$ =3.7 d) has been investigated by means of high-resolution ( $R \sim 48000$ ) spectral analysis and multi-band (Johnson $B V R I$ and StrÃ¶mgren $v b y$ ) light curve modeling. The physical parameters of the components have been found to be $M_{1} = 4.26 \pm 0.10$ M $_{⊙}$ , $R_{1} = 3.72 \pm 0.05$ R $_{⊙}$ , $T_{eff1} = 16600 \pm 520$ K, and $M_{2} = 5.14 \pm 0.09$ M $_{⊙}$ , $R_{2} = 7.32 \pm 0.03$ R $_{⊙}$ , $T_{eff2} = 15000 \pm 500$ K for the primary and secondary, respectively. The orbital inclination is $i = 87.0 \pm 0.2$ deg. The distance to MQ Cen has been derived to be $d = 2460 \pm 310$ pc which locates it in the Crux OB1 association. However, the age of MQ~Cen ( $\sim 70$ Myr) is higher than the one reported for the Crux OB1 association ( $\sim$ 6 Myr). The derived masses are implying a spectral type of B5 for the primary and B4 for the secondary component. Nevertheless, the secondary component, which is more massive, appears to be cooler than the primary component: It has completed its lifetime on the main-sequence and it is now positioned at the turn-off point of the giant branch, meanwhile the less massive primary component is still staying on the main-sequence.

14 pages, 7 figures and 4 tables, accepted for publication in Astrophysics and Space Science