A nonlinear kinetic theory , combining cosmic-ray ( CR ) acceleration in supernova remnants ( SNRs ) with their gas dynamics , is used to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5–50 yr . This spherically symmetric model is approximately applied to the different features of the SNR which consist of ( i ) a blue supergiant wind and bubble , and ( ii ) of the swept-up red supergiant ( RSG ) wind structures in the form of an H II region , an equatorial ring ( ER ) , and an hourglass region . The RSG wind involves a mass loss rate that decreases significantly with elevation above and below the equatorial plane . The model adapts recent three-dimensional hydrodynamical simulations by Potter et al . in 2014 that use a significantly smaller ionized mass of the ER than assumed in the earlier studies by the present authors . The SNR shock recently swept up the ER , which is the densest region in the immediate circumstellar environment . Therefore , the expected gamma-ray energy flux density at TeV energies in the current epoch has already reached its maximal value of \sim 10 ^ { -13 } erg cm ^ { -2 } s ^ { -1 } . This flux should decrease by a factor of about two over the next 10 years .