GW170817 was really an event of the century that has opened thewindow to the frontier of multi-messenger astronomy and astrophysics. Gravitational waves from most likely the merging neutron stars weredetected in LIGO-Virgo collaboration, GRB was observed in Fermi-GBM, andobserved optical and near-infrared emissions in several Telescopes areconsistent with those from radiative decays of r-process nuclei whichare predicted theoretically in the nucleosynthesis calculation. Neutrinos were not detected unfortunately because of their too low fluxfrom GW170817 that occurred at a distance 0.13 Gly away.  We now await anearby GW event (probably once per one thousand years in our Milky Way)for spectroscopic observation of still unidentified**r-process elementsfrom neutron star mergers (NSMs). Not only the NSMs but core-collapse supernovae (of bothmagneto-hydrodynamic jet supernovae; MHD Jet-SNe, and neutrino-drivenwind supernovae; ν-SNe) are viable candidates for the r-process sites. NSMs could not contribute to the early Galaxy for cosmologically longmerging time-scale for too slow GW radiation, while MHD Jet-SNe canexplain the “universality” in the observed abundance pattern in metalpoor stars.  

Prof. Taka Kajino received his PhD in theoretical nuclear physics from the university of Tokyo in 1984.He is a professor at the National Astronomical Observatory of Japan since 1993 and professor  at the university of Tokyo since 1994. He became a distinguished professor at Beihang University in 2017.