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Paper: Wide Tertiary Companions to Nearby Spectroscopic Binaries: A Close Look with Gemini-North AO
Volume: 448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun
Page: 547
Authors: Allen, P. R.; Close, L.
Abstract: We report on the preliminary findings of a multi-epoch, common proper motion (CPM) search for tertiary companions to known, nearby spectroscopic binary systems. Simulations of the star forming environment indicate that, in order to produce the very small separations of such systems, a third member can carry away angular momentum, tightening the binary. This third member typically has a low-mass and remains bound to the system. We use NIRI-Altair AO imaging on Gemini-North to search for close tertiary companions to a sample of 91 spectroscopic binaries. We collect the data in two narrow-band filters separated by approximately one year. The two filters are centered just outside of the 1.6 μm methane feature (CH4short) and just inside it (CH4long). This allows for two forms of candidate identification: 1) CPM and 2) methane dropout if the object is a T dwarf. At this time, we have obtained and analyzed 60 multi-epoch fields. We confirm a previously known CPM companion and identify three sub-stellar candidates and two M dwarf candidates.
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