This invaluable Encyclopaedia, now in its second edition, conveys a deep and coherent understanding of the stellar phenomena, and basic astrophysics of stars, galaxies, clusters of galaxies and other heavenly bodies of reader?s interest. Its main objective is to present subjective information about physical properties and chemical composition of celestial objects. This edition also included biographical outline and theoretical contribution of the eminent astrophysicists. Approximately 101 entries are included in this encyclopaedia in A-Z format. Topics included in this edition are stellar dynamics and evolution; galaxy formation; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics. This encyclopaedia is mainly compiled for undergraduate and graduate students, but it will also useful for researchers and teachers of Physics and its allied subjects.