 In larger stars , fusion continues until the iron core has grown so large ( more than 1 @.@ 4 M ☉ ) that it can no longer support its own mass . This core will suddenly collapse as its electrons are driven into its protons , forming neutrons , neutrinos , and gamma rays in a burst of electron capture and inverse beta decay . The shockwave formed by this sudden collapse causes the rest of the star to explode in a supernova . Supernovae become so bright that they may briefly outshine the star 's entire home galaxy . When they occur within the Milky Way , supernovae have historically been observed by naked @-@ eye observers as " new stars " where none seemingly existed before . 
 In larger stars , fusion <a href='uninflect' title='1'><mark>continues</mark></a> until the iron core <a href='been_done' title='2'><mark>has</mark></a> grown so large ( more than 1 @.@ 4 M ☉ ) that it can no longer support its own mass . This core will suddenly collapse as its electrons are driven into its protons , forming neutrons , neutrinos , and gamma rays in a burst of electron capture and inverse beta decay . The shockwave formed by this sudden collapse <a href='uninflect' title='3'><mark>causes</mark></a> the rest of the star to explode in a supernova . Supernovae become so bright that they may briefly outshine the star <a href='null_genetive' title='4'><mark>'s</mark></a>entire home galaxy . When they occur within the Milky Way , supernovae <a href='been_done' title='5'><mark>have</mark></a> historically been observed by naked @-@ eye observers as " new stars " where none seemingly existed before . 
In larger stars , fusion continue til the iron core done grown soo large ( more than 1 @.@ 4 M ☉ ) that it can no longer support its own mass . This core gon suddenly collapse as its electrons are driven into its protons , forming neutrons , neutrinos , and gamma rays in a burst of electron capture and inverse beta decay . da shockwave formed by dis sudden collapse cuz the rest of the star to explode in a supernova . Supernovae become so bright that they may briefly outshine the star  entire home galaxy . When they occur within the Milky Way , supernovae done historically been observed by naked @-@ eye observers as " new stars " where none seemingly existed before .