Star burst: supernova ASASSN-15lh is defying explanation Beijing Planetarium/Jin MaBy Rebecca BoyleWhat we thought was the largest supernova ever observed might in fact be the death gasp of a star being swallowed by a black hole. The flash, called ASASSN-15lh, was spotted in June 2015 in the All Sky Automated Survey for SuperNovae (ASAS-SN). Later...