Tertiary companions to close spectroscopic binaries

Abstract

Preliminary results of a survey of nearby solar-type spectroscopic binaries (SB) with orbital periods 1 < P 1 < 30 days for tertiary companions are presented. Observations with adaptive optics and data from the 2MASS sky survey permitted to discover new tertiary components and to sharpen statistical limits on their frequency. We find that 0.86 ± 0.07 SBs with P1 < 5 d have tertiaries, but this fraction drops to 0.49 ± 0.06 for P1 < 5 d. The periods of tertiary companions are distributed in a wide range, from 2 to 105 yr, with most frequent periods of few thousand years. © 2008 Springer-Verlag Berlin Heidelberg.