The long-term optical evolution of the black hole candidate MAXI J1659-152

We present 5 years of optical and infrared data of the black hole candidate MAXI J1659-152 covering its 2010 outburst, decay and quiescence. Combining optical data taken during the outburst decay, we obtain an orbital period of 2.414 \(\pm\) 0.005 h, in perfect agreement with the value previously measured from X-ray dips. In addition, we detect a clear H\(\alpha\) excess in MAXI J1659-152 with data taken during the outburst decay. We also detect a single hump modulation most likely produced by irradiation. Assuming that the maximum occurs at orbital phase 0.5, we constrain the phase of the X-ray dips to be ~ 0.65. We also detect the quiescent optical counterpart at r' = 24.20 \(\pm\) 0.08, I = 23.32 \(\pm\) 0.02 and H = 20.7 \(\pm\) 0.1. These magnitudes provide colour indices implying an M2-M5 donor star assuming 60% contribution from a disc component in the r'-band.