We describe the discovery of a likely brown dwarf ( BD ) companion with a minimum mass of 31.7 \pm 2.0 M _ { Jup } to GSC 03546-01452 from the MARVELS radial velocity survey , which we designate as MARVELS-6b .
For reasonable priors , our analysis gives a probability of 72 % that MARVELS-6b has a mass below the hydrogen-burning limit of 0.072 M _ { \sun } , and thus it is a high-confidence BD companion .
It has a moderately long orbital period of 47.8929 ^ { +0.0063 } _ { -0.0062 } days with a low eccentricty of 0.1442 ^ { +0.0078 } _ { -0.0073 } , and a semi-amplitude of 1644 ^ { +12 } _ { -13 } m~ { } s ^ { -1 } .
Moderate resolution spectroscopy of the host star has determined the following parameters : T _ { eff } = 5598 \pm 63 , \log { g } = 4.44 \pm 0.17 , and [ Fe/H ] = +0.40 \pm 0.09 .
Based upon these measurements , GSC 03546-01452 has a probable mass and radius of M _ { * } = 1.11 \pm 0.11 ~ { } M _ { \sun } and R _ { * } = 1.06 \pm 0.23 ~ { } R _ { \sun } with an age consistent with less than \sim 6 Gyr at a distance of 219 \pm 21 pc from the Sun .
Although MARVELS-6b is not observed to transit , we can not definitively rule out a transiting configuration based on our observations .
There is a visual companion detected with Lucky Imaging at 7.7″ from the host star , but our analysis shows that it is not bound to this system .
The minimum mass of MARVELS-6b exists at the minimum of the mass functions for both stars and planets , making this a rare object even compared to other BDs .
It also exists in an underdense region in both period/eccentricity and metallicity/eccentricity space .