In this paper , continuation of Gil de Paz et al .
( Paper I ) , we derive the main properties of the stellar populations in the Blue Compact Dwarf galaxy Mrk~86 .
Ages , stellar masses , metallicites and burst strengths have been obtained using the combination of Monte Carlo simulations , a maximum likelihood estimator and Cluster and Principal Component Analysis .
The three stellar populations detected show well defined properties .
We have studied the underlying stellar population , which shows an age between 5-13 Gyr and no significant color gradients .
The intermediate aged ( 30 Myr old ) central starburst show a very low dust extinction with high burst strength and high stellar mass content ( \sim 9 \times 10 ^ { 6 } M _ { \sun } ) .
Finally , the properties of 46 low-metallicity ( \sim 1/10 Z _ { \sun } ) star-forming regions were also studied .

The properties derived suggest that the most recent star-forming activity in Mrk~86 was triggered by the evolution of a superbubble originated at the central starburst by the energy deposition of stellar winds and supernova explosions .
This superbubble produced the blowout of a fraction of the interstellar medium at distances of about 1 kpc with high gas surface densities , leading to the activation of the star formation .

Finally , different mechanisms for the star formation triggering in this massive central starburst are studied , including the merging with a low mass companion and the interaction with UGC~4278 .
We have assumed a distance to Mrk~86 of 6.9 Mpc .