The quasar 3C~286 is one of two compact steep spectrum sources detected by
the {\it Fermi}/LAT. Here, we investigate the radio properties of the
parsec(pc)-scale jet and its (possible) association with the γ-ray
emission in 3C~286. The Very Long Baseline Interferometry (VLBI) images at
various frequencies reveal a one-sided core--jet structure extending to the
southwest at a projected distance of ∼1 kpc. The component at the jet base
showing an inverted spectrum is identified as the core, with a mean brightness
temperature of 2.8×109~K. The jet bends at about 600 pc (in
projection) away from the core, from a position angle of −135∘ to
−115∘. Based on the available VLBI data, we inferred the proper motion
speed of the inner jet as 0.013±0.011 mas yr−1 (βapp​=0.6±0.5), corresponding to a jet speed of about 0.5c at an inclination
angle of 48∘ between the jet and the line of sight of the observer. The
brightness temperature, jet speed and Lorentz factor are much lower than those
of γ-ray-emitting blazars, implying that the pc-scale jet in 3C~286 is
mildly relativistic. Unlike blazars in which γ-ray emission is in
general thought to originate from the beamed innermost jet, the location and
mechanism of γ-ray emission in 3C~286 may be different as indicated by
the current radio data. Multi-band spectrum fitting may offer a complementary
diagnostic clue of the γ-ray production mechanism in this source.Comment: 9 pages, 4 figures, accept for publication in MNRA