Particles can materialize in conjunction with their antiparticles, and fields can undergo fluctuations in their values. See Higgs fields. The energy of the particles is highest in the inner belt. The outer zone is composed chiefly of electrons, the inner of protons. A theory of Hoyle and Narlikar in which the masses of fundamental particles are assumed to vary with time in a manner that precisely accounts for the Hubble redshift law.
Periods vary widely in length and even regularity.
Novae and supernovae are classed as variables. A star whose light varies. A star that varies in luminosity. The first variable discovered in a given constellation has the letter R preceding the name of the constellation. Then S, . . .