  a supernova is a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the sun or any ordinary star is expected to emit over its entire life span, before fading from view over several weeks or months.  the extremely luminous burst of radiation expels much or all of a star's material  at a velocity of up to  (10% of the speed of light), driving a shock wave  into the surrounding interstellar medium. this shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. a great proportion of primary cosmic rays comes from supernovae.{{cite journal | volume=339 | pages=807â811 | title=detection of the characteristic pion-decay signature in supernova remnants | date=2013-02-15 | doi=10.1126/science.1231160 | url=http://www.sciencemag.org/content/339/6121/807.full | publisher=american association for the advancement of science | accessdate=2013-02-14 | issue=6424 | last1=ackermann | first1=m. | last2=ajello | first2=m. | last3=allafort | first3=a. | last4=baldini | first4=l. | last5=ballet | first5=j. | last6=barbiellini | first6=g. | last7=baring | first7=m. g. | last8=bastieri | first8=d. | last9=bechtol | first9=k. | journal=science |arxiv = 1302.3307 |bibcode = 2013sci...339..807a | last10=bellazzini | first10
Light_sources Space_plasmas Standard_candles Stellar_evolution Stellar_phenomena Supernovae