2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/6632The accretion of a cloud of hydrogen at the surface of a small, heavy star produces a high energy mostly dissipated by electromagnetic radiation. The combination of the absorption and the redshift of this radiation by hydrogen explains all spectral observations: shapes of the broad lines, and their anti-correlation with the radio-loudness, lack of lines in front of the Lyman forest, value zb = 0.062 of the periodicity of the redshifts, correlation of a high redshift with a thermal spectrum attributed to dust. These properties are deduced from usual laws of physics without new parameters, they do not require any non baryonic matter.7 pagesAstrophysicstext