Supernovae and Comic Rays

W. BAADE, Mt. Wilson Observatories and
F. ZWICKY, California Institute of Technology

Supernovae flare up in every stellar system (nebula) once in several centuries. The lifetime of a supernova is about twenty days and its absolute brightness at maximum may be as high as M_VIS = −19. The visible radiation, L, of a supernova, is about 10⁸ times the radiation of our sun, that is, L = 3.78 × 10⁴¹ ergs/sec. Calculations indicate that the total radiation, visible and invisible, is of the order L = 3.78 × 10⁴⁸ ergs/sec. The supernova therefore emits during its life a total energy E > 3.78 × 10⁵³ ergs. If supernovae initially are quite ordinary stars of mass M < 10³⁴ gm, E/c² is of the same order as M itself. In the supernova process mass in bulk is annihilated. In addition the hypothesis suggests itself that cosmic rays are produced by supernovae. Assuming that in every nebula one supernova occurs every thousand years, the intensity of the cosmic rays to be observed on the earth should be of the order s = 2 × 10⁻³ erg/cm² sec. The observational values are about s = 3 × 10⁻³ erg/cm² sec. (Millikan, Regener). With all reserve we advance the view that supernovae represent the transitions from ordinary stars into neutron stars, which in their final stages consist of extremely closely packed neutrons.