Astrophysics

This second part bearing the title of \underline{Astrophysics} is an introduction to more complex themes tha are usually studied on specialised courses lasting longer than one year, like the courses for students of Astronomy. Among the contents of this part are stellar spectra, the blackbody, the classification of stars according to spectrum type and luminosity, the classical, relativistic and gravitational Doppler effect, the gravitational deflection for stars and quasars, tangential and radial velocities of stars, spectroscopic orbits, visual or photometric binary stars, the determination of stellar radii and masses, of neutron stars and black holes with the mass function, an overview if stellar evolution up to the stage of pre-supernovae and supernovae of small and large mass. Also galaxy clusters, the Hubble law, quasars and galaxies with equally large red shifts determined by means of their forbidden lines are briefly outlined. The density of black holes that could form from the collapse of galaxies is also computed. The paragraph of Newtonian cosmology is integrated with some concepts of a conference held in Asiago (Italy) by Prof. F. Lucchin