A star that derives its energy from the conversion of hydrogen into helium in its core. The Sun is a main sequence star. Mass The quantity of matter in an object, usually expressed in kilograms or pounds. An elementary particle with zero electric charge and very little mass . Neutrinos are produced copiously by many of the nuclear reactions powering stars.
Neutrinos interact only very weakly with other matter.
Neutron A particle with zero electric charge and a mass only slightly greater than that of the proton . A compact star consisting predominantly of neutrons . Neutron stars have masses in the range of about one to three solar masses and sizes of around 12 miles. The sudden brightening of a white dwarf that is accreting hydrogen-rich matter from a nearby companion star. Nuclear burning Reactions in which nuclei of atoms combine to form nuclei of heavier atoms and release energy.