We have a total of 25 high-resolution spectra from three spectrographs. At many orbital phases, prominent absorption lines show a clear double-lined signature when inspected by eye. We find that KIC 9246715 is an excellent target for obtaining radial velocity curves for both stars in the binary as the stellar flux ratio is close to unity. A long time span of observations was necessary due to the 171.277-day orbital period and visibility of the Kepler field from the observing sites.

We obtained 13 high-resolution optical spectra from the Fred Lawrence Whipple Observatory (FLWO) 1.5-m telescope in Arizona using the Tillinghast Reflector Echelle Spectrograph (TRES) from 2012 March through 2013 April. The wavelength range for TRES is 3900–9100 Å, and the resolution for the medium fiber used is 44,000. The spectra were extracted and blaze-corrected with the pipeline developed by \citet{buc10}.

We also obtained ten high-resolution optical spectra from the Apache Point Observatory (APO) 3.5-m telescope in New Mexico using the Astrophysical Research Consortium Echelle Spectrograph (ARCES) from 2012 June through 2013 September. The wavelength range for ARCES is 3200–10,000 Å with no gaps, and the average resolution is 31,000. We reduced the data using standard echelle reduction techniques and Karen Kinemuchi’s ARCES cookbook (private communication)¹¹http://astronomy.nmsu.edu:8000/apo-wiki/wiki/ARCES#reduction - ARCES Data Reduction Cookbook.

We finally obtained two near-IR spectra of KIC 9246715 from the Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey \citep{ala15}. The wavelength range for APOGEE is 1.5–1.7 \(\mu\)m with a nominal resolution of 22,500. The pair of spectra were reduced with the standard APOGEE pipeline, but not combined.

Because the observations come from three different spectrographs at two different observatory sites, it is critical to apply a consistent wavelength solution that yields the same radial velocity zeropoint for all observations. This zeropoint is a function of the atmospheric conditions at the observatory and the instrument being used. Typically such a correction can be done with RV standard stars after a wavelength solution has been applied based on ThAr lamp observations. However, we lacked RV standard star observations, and some of the earlier ARCES observations had insufficiently frequent ThAr calibration images to arrive at a reliable wavelength solution. (We subsequently took ThAr images more frequently to address the latter issue.) To arrive at a consistent velocity zeropoint for all spectra, we use TelFit \citep{gul14} to generate a telluric line model of the O2 A-band (7595–7638 Å) with \(R=31,000\) at STP. We then shift the ARCES and TRES spectra in velocity space using the broadening function technique (see Section \ref{bf}) so they all line up with the TelFit model. The shifts range from \(-0.88\) to \(2.18\) km s\({}^{-1}\), with the majority having a magnitude \(<0.3\) km s\({}^{-1}\).