An astronomical object refers to any celestial body or structure observed in the universe, representing diverse phenomena ranging from stellar remnants to vast clouds of gas. These objects are governed by the principles of gravity, thermodynamics, and nuclear physics. Classification depends on composition, energy output, and physical state; examples include stars, which generate energy through nuclear fusion in their cores; galaxies, which are massive, gravitationally bound collections of stars, dust, and dark matter; and nebulae, which are vast interstellar clouds of dust and gas where stars are often formed. The study of these objects requires understanding the forces that shape them over cosmological timescales, dictating their lifespan and evolution within the observable cosmos.