The gravitation forces are such that protons and electrons combine to form neutrons.
La Terre constituée de la même matière serait réduite à une sphère d’un mètre de diamètre
There exists another type of black hole called massive and supermassive, situated in the heart of the galaxies, and the mass of which is several millions or several billions times that of the mass of the Sun.
At the centre of the nebula there is a pulsar, a neutron star
At the centre of the nebula there is a stellar black hole “visible” by the effects on its surrounding environment.