Infrared Detection of Low-Mass Secondaries in Spectroscopic Binaries

This paper outlines an infrared spectroscopic technique to measure the radial velocities of faint secondaries in known single-lined binaries. The paper presents our H-band observations with the Cryogenic Echelle (CSHELL) and the Phoenix spectrographs and describes detections of three low-mass secondaries in main-sequence binaries, G147-36, G164-67, and HD 144284, with mass ratios of 0.562 ± 0.011, 0.423 ± 0.042, and 0.380 ± 0.013, respectively. The latter is one of the smallest mass ratios derived to date for detached main-sequence stars.