Spectroscopic orbits of two short-period early-type binaries using two-dimensional cross-correlations*
Complejo Astronómico El Leoncito (CASLEO), San Juan, Argentina
2 Observatorio Astronómico de Córdoba (OAC), Argentina
Corresponding author: J. F. González, firstname.lastname@example.org
Accepted: 24 March 2003
We apply the two-dimensional cross-correlation technique TODCOR to derive spectroscopic orbits for the two B-type double-lined spectroscopic binaries HD 66066A and HD 315031, previously mentioned as blue straggler candidates of the open clusters NGC 2516 and NGC 6530, respectively. Reliable radial velocities for both components are measured even for orbital phases for which the separation between the spectral lines are about 0.5 times the quadratic sum of the full-width at half-maximum of the lines. Both binaries have circular orbits and the orbital periods are 1.67 and 1.38 days for HD 66066A and HD 315031, respectively. We calculate minimum masses with errors of 3–5% and obtain the projected radii from the line widths. We derive absolute stellar parameters which are consistent with the age and distance of the clusters. Both binary systems are formed by main-sequence stars and it is expected that they will experience mass-transfer between their components before the end of the core H-burning stage. HD 315031 is likely a triple system as suggested by the variation of the center-of-mass velocity.
Key words: techniques: radial velocities / binaries: spectroscopic / stars: individual: HD 66066A, HD 315031 / open clusters and associations: individual: NGC 2516, NGC 6530
The observations presented here were obtained at the Complejo Astronómico El Leoncito (CASLEO), which is operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET) and the National Universities of La Plata, Córdoba and San Juan.
© ESO, 2003