The associate star responsible for triggering an unusual sort of supernova has been identify after 20 long time of searching , confirming our ideas on how these events occur . " This is like a criminal offense view , and we finally key out the robber , " aver , University of California ( UC ) , Berkeley Professor Alex Filippenko , " The companion star stole a gang of H before the primary star blow up . "
Supernovae have been classified depending on their spectrums , reflecting the conditions that caused the asterisk that formed them to explode . character IIb supernova are one of the rarest sort . While Type Ib supernova have no hydrogen and minuscule silicon , normal Type II show hydrogen . case IIb , on the other hired hand , start off looking like a typical Type II supernova before switching to appear more like a Ib supernova .
Both Type II and Ib supernovae are a result of massive stars running out of fuel contribute to crumble , follow by a reverberate explosion , unlike thevery different origin of Ia upshot . The difference is that in Tybe Ib supernova the hydrogen has been expelled bystrong stellar winds , orstripped aside by a companion star , before the explosion happens . This is potential because old stars become layered with hard elements at their gist and hydrogen on the outside .
Type IIb supernovae ab initio have only a little hydrogen in their spectrum , but enough to be classified as Type II . However , this disappears after the brightness has passed its efflorescence . It is thought that in these cases , most of the hydrogen has been removed by a large companion virtuoso . Enough is left to be initially visible , but the outermost layerbecomes gauzy as the gasses rush aside after the detonation .
Type IIb supernova are rare , and I close down enough for designation of the fellow whiz are particularly scarce . ConsequentlySN 1993J , which occurred a cosmically tiny 11 million light years away in Galax urceolata M81 , has become one of themost intensely studied stellar explosion of all time . However , until now the identity of the fellow traveler star has remained a mystery .
“ A binary system is likely required to mislay the absolute majority of the primary star ’s hydrogen envelope prior to the explosion . The problem is that , to date , direct observations of the predicted binary companion star have been difficult to obtain since it is so faint relative to the supernova itself , ” says Dr. Ori Fox , also of Berkeley . While this is a trouble with finding all supernova companions , the search was particularly difficult in this instance because the field around the supernova is crowded with asterisk .
However , inThe Astrophysical JournalFox and Flippenko have identify a potential candidate , based on Hubble measurements of its intense ultraviolet light , an anticipated feature of speech of a star topology that has acquired additional hydrogen in this mode . The determination increases confidence in our models of Type IIb supernovae , and indeed Type II event in ecumenical .
