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Paper: |
Binaries from FEROS Radial Velocity Survey |
Volume: |
318, Spectroscopically and Spatially Resolving the Components of Close Binary Stars |
Page: |
283 |
Authors: |
Setiawan, J.; da Silva, L.; Pasquini, L.; Hatzes, A.P.; von der Luhe, O.; Girardi, L.; Guenther, E. |
Abstract: |
At least eleven binary systems have been found from our radial velocity (RV) survey (precision ∼ 25 ms-1 of eighty-three G and K evolved stars using FEROS at the 1.52m ESO in La Silla and high resolution echelle-spectrograph at 2m-Alfred-Jensch-telescope in Tautenburg, Germany. We used the simultaneous calibration method and the iodine absorption-cell technique to measure the RV variations. Orbital elements have been derived from the RV curves of six binaries. The stellar companions have minimum masses (m sin i) from 0.1 up to 0.6 Solar masses and orbital semi-major axes between 0.2 and 3.6AU. Two special cases are found among them: first, in one system, HD 156111, the sin i has been determined which permitted us to derive the companion's real mass, and second, we found a dependence between the RV variation of HD 62644 induced by its companion, and chromospheric activity of the primary star. For the remaining five stars we do not have enough measurements to obtain the complete orbital solutions. Finally, we report two other giants in our sample, HD 224533 and HD 27256, which might have brown-dwarf companions. |
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