Discovery and Characterization of 3000+ Main-Sequence Binaries from APOGEE Spectra

Understand

We develop a data-driven spectral model for identifying and characterizing spatially unresolved multiple-star systems and apply it to APOGEE DR13 spectra of main-sequence stars.

• Binaries and triples are identified as targets whose spectra can be significantly better fit by a superposition of two or three model spectra, drawn from the same isochrone, than any single-star model.
• From an initial sample of $\sim$20,000 main-sequence targets, we identify $\sim$2,500 binaries in which both the primary and secondary star contribute detectably to the spectrum, simultaneously fitting for the velocities and stellar parameters of both components.
• We additionally identify and fit $\sim$200 triple systems, as well as $\sim$700 velocity-variable systems in which the secondary does not contribute detectably to the spectrum.