  We present a super-Earth orbiting close to the inner edge of the habitable
zone of the cool dwarf star K2-286 (EPIC 249889081), detected with data from
the K2 mission in its $15^{th}$ campaign. The planet has radius of $2.1\pm0.2$
R$_{\oplus}$, near the 1.5 - 2.0 R$_{\oplus}$ gap in the radii distribution.
The equilibrium temperature is $347^{+21}_{-11}$ K, cooler than most of the
small planets with well measured masses, and the orbital period is
$27.359\pm0.005$ days. K2-286, located at a distance of $76.3\pm0.3$ pc, is an
M0V star with estimated effective temperature of $3926\pm100$ K, less active
than other M dwarf stars hosting exoplanets. The expected radial velocity
semi-amplitude induced by the planet on the star is $1.9^{+1.3}_{-1.2}$
m$\cdot$s$^{-1}$, and the amplitude of signals in transit transmission
spectroscopy is estimated at $5.0\pm3.0$ ppm. Follow-up observations for mass
measurements and transit spectroscopy should be desirable for this relatively
bright target ($m_V=12.76, m_{Ks}=9.32$) hosting a transiting super-Earth
within the inner edge of the habitable zone.
