(Proposal ID) S15B-121

(PI) Helminiak, Krzysztof

(Proposal Title)
IR spectroscopy of detached eclipsing binaries - spotting cool companions

(Abstract)
We propose to use IRCS in the echelle mode to observe a sample of detached 
eclipsing binaries (DEBs) selected mainly (but not only) from the All-Sky 
Automated Survey (ASAS) catalog. Previous spectroscopy done in visual reveals 
a presence of cool stars (late K or M-type) in these systems, not seen 
directly in the spectra. These cool stars are: (1) secondary components of 
single-lined (SB1) eclipsing binaries, (2) secondaries of a pair in very 
unique, double-double SB2+SB1 multiples. In any case, their radial velocities 
(RVs) are necessary to derive a complete set of physical parameters of a given 
object. All these systems are particularly useful to test models of stellar 
structure, and the architecture of the rare multiples informs us about 
formation mechanisms, or dynamical interactions. 
In the long term, the proposed observations will also be used to perform 
spectral analysis of the cool components to independently derive their 
effective temperatures, metallicities, etc.