A brown dwarf companion to the intermediate-mass star HR 6037

Context. The frequency of brown dwarf and planetary-mass companions around intermediate-mass stars is still unknown. Imaging and radial velocity surveys have revealed a small number of substellar companions to these stars.
Aims: In the course of an imaging survey we detected a visual companion to the intermediate-mass star HR 6037. We here confirm it as a co-moving substellar object.
Methods: We present two epoch observations of HR 6037, an A6-type star with a companion candidate at 6farcs67 and position angle of 294 degrees. We also analyze near-infrared spectroscopy of the companion.
Results: Two epoch observations of HR 6037 have allowed us to confirm HR 6037 B as a co-moving companion. Its J and H band spectra suggest that the object has a spectral type of M9, with a surface gravity that is intermediate between a 10 Myr dwarf and a field dwarf of the same spectral type. The comparison of its K_s-band photometry with evolutionary tracks allows us to derive a mass, effective temperature, and surface gravity of 62±20 M_Jup, T_eff = 2330±200 K, and log g = 5.1±0.2, respectively. The low binary mass ratio, q 0.03, and its long orbital period, 5000 yr, make HR 6037 a rare and uncommon binary system.

Based on observations collected at the Paranal Observatory under programs 272.D-5068(A), 77.D-0147(A), and 285.C-5008(A).