We report the discovery via radial velocity measurements of a short-period ( P = 2.430420 \pm 0.000006 days ) companion to the F-type main sequence star TYC 2930-00872-1 .
A long-term trend in the radial velocity data also suggests the presence of a tertiary stellar companion with P > 2000 days .
High-resolution spectroscopy of the host star yields T _ { eff } = 6427 \pm 33 ~ { } { K } , \log { g } = 4.52 \pm 0.14 , and [ Fe/H ] = -0.04 \pm 0.05 .
These parameters , combined with the broad-band spectral energy distribution and a parallax , allow us to infer a mass and radius of the host star of M _ { 1 } = 1.21 \pm 0.08 ~ { } { M _ { \odot } } and R _ { 1 } = 1.09 _ { -0.13 } ^ { +0.15 } ~ { } { R _ { \odot } } .
The minimum mass of the inner companion is below the hydrogen burning limit , however the true mass is likely to be substantially higher .
We are able to exclude transits of the inner companion with high confidence .
Further , the host star spectrum exhibits a clear signature of Ca H and K core emission indicating stellar activity , but a lack of photometric variability and small v \sin I suggest the primary ’ s spin axis is oriented in a pole-on configuration .
The rotational period of the primary estimated through an activity-rotation relation matches the orbital period of the inner companion to within 1.5 \sigma , suggesting that the primary and inner companion are tidally locked .
If the inner companion ’ s orbital angular momentum vector is aligned with the stellar spin axis as expected through tidal evolution , then it has a stellar mass of \sim 0.3 - 0.4 ~ { } { M _ { \odot } } .
Direct imaging limits the existence of stellar companions to projected separations < 30 AU .
No set of spectral lines and no significant flux contribution to the spectral energy distribution from either companion are detected , which places individual upper mass limits of M _ { \left \ { 2 , 3 \right \ } } \lesssim 1.0 ~ { } { M _ { \odot } } , provided they are not stellar remnants .
If the tertiary is not a stellar remnant , then it likely has a mass of \sim 0.5 - 0.6 ~ { } { M _ { \odot } } , and its orbit is likely significantly inclined from that of the secondary , suggesting that the Kozai-Lidov mechanism may have driven the dynamical evolution of this system .