The beryllium yield per supernova would increase as the interstellar abundances of carbon and oxygen increase, contrary to observations. A supernova is born when, during the dying moments of a star, under the force of gravity and internal radiation, the core contracts and is heated. This results in a tremendous explosion rivaling the combined output of all the rest of the stars in the Galaxy. It is this shock that is thought to accelerate the cosmic rays. We are confident that shock waves in astronomical plasmas can accelerate particles to cosmic ray velocities, because we have observed this happening in our own solar system.
Shock waves form in the solar wind plasma under a variety of circumstances.
Behind the supernova shock, the ejecta is highly enriched in carbon, oxygen, magnesium, aluminum, silicon, calcium, iron and nickel, synthesized under the tremendous heat and pressure during the star's last years and final death throes. Indeed, as the shock plows into the interstellar medium and slows down, the grains continue moving at more than 1,500 miles per second, passing through the slowing plasma and catching up with the shock wave. As this dust passes through the plasma, atoms torn from the grains become electrically charged, and those shed in the vicinity of the shock are accelerated to cosmic ray velocities. Evidence for the formation of massive amounts of high velocity dust in supernova ejecta came from observations of the optical absorption and infrared re-emission of light from the Supernova 1987a. This aluminum is thought to be in the dust grains shot out from supernovae.