MARVELS-1b: A SHORT-PERIOD, BROWN DWARF DESERT CANDIDATE FROM THE SDSS-III MARVELS PLANET SEARCH

摘要: We present a new short-period brown dwarf (BD) candidate around the star TYC 1240-00945-1. This was discovered in first year of Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part Sloan Digital Sky (SDSS) III, and we designate BD as MARVELS-1b. MARVELS uses technique dispersed fixed-delay interferometery to simultaneously obtain radial velocity (RV) measurements for 60 objects per field using single, custom-built instrument that fiber fed from SDSS 2.5 m telescope. From our 20 RV spread over ~370 day time baseline, derive Keplerian orbital fit with semi-amplitude K = 2.533 ± 0.025 km s^(–1), period P 5.8953 0.0004 days, eccentricity consistent circular. Independent follow-up data confirm orbit. Adopting mass 1.37 0.11 M_☉ slightly evolved F9 host star, infer companion has minimum 28.0 1.5 M_(Jup), semimajor axis 0.071 0.002 AU assuming an edge-on orbit, probably tidally synchronized. find no evidence coherent intrinsic variability at levels greater than few millimagnitudes. The priori transit probability ~14%. Although transits, cannot definitively rule them out radii ≲ R_(Jup).