  The secondary photometric standard star #79 for the FS Aur field (Henden &
Honeycutt 1997) designated as [HH97] FS Aur-79 (GSC 1874 399) is a short period
(0.2508 days) eclipsing binary whose light curve is a combination of the
$\beta$ Lyr and BY Dra type variables. High signal-to-noise multi-color
photometry were obtained using the USNO 1-m telescope. These light curves show
asymmetry at quadrature phases (O'Connell effect), which can be modeled with
the presence of star spots. A low resolution spectrum obtained with the 3.5-m
WIYN telescope at orbital phase 0.76 is consistent with a spectral type of dK7e
and dM3e. A radial velocity curve for the primary star was constructed using
twenty-four high resolution spectra from the 9.2 m HET. Spectra show H-alpha
and H-beta in emission confirming chromospheric activity and possibly the
presence of circumstellar material. Binary star models that simultaneously fit
the U, B, V, R and RV curves are those with a primary star of mass 0.59+-0.02
Msun, temperature 4100+-25 K, mean radius of 0.67 Rsun, just filling its Roche
lobe and a secondary star of mass 0.31+-0.09 Msun, temperature 3425+-25 K, mean
radius of 0.48 Rsun, just within its Roche lobe. An inclination angle of 83+-2
degrees with a center of mass separation of 1.62 Rsun is also derived. Star
spots, expected for a rotation period of less than a day, had to be included in
the modeling to fit the O'Connell effect.
