Astrophysics is a branch of space science that employs the methods and principles of physics and chemistry to ascertain the nature of the astronomical objects, rather than their positions or motions in space. It is a sub-field of astronomy and astrophysics is the branch of astronomy that employs the methods and principles of physics and chemistry in the study of celestial objects, phenomena, and the universe as a whole. In Hebrew, astrophysics is known as אסטרופיזיקה (Astrifizika). The term is often translated in other languages as well, such as Astrophysik in German, Astrofísica in Spanish and Portuguese, and Astrophysique in French. Astrophysics seeks to understand the universe and its contents through a fundamental approach that combines observation, theoretical explanation, and experimental verification. Key areas of study in astrophysics include the physical properties and interactions of matter and radiation in the cosmos, the structure, evolution, and dynamics of celestial objects, and the large-scale structure and evolution of the universe itself. Astrophysicists apply the laws of physics and chemistry to explain phenomena such as the life cycles of stars, the formation of galaxies, the behavior of black holes, and the origin and evolution of the universe.
Subfield of astronomy
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space-what they are, rather than where they are", which is studied in celestial mechanics.