Our Star: The Sun
Our Sun is an ordinary star, just one among hundreds of billions of stars in the Milky Way Galaxy. As the only star we can observe in detail, it provides a basis for our understanding of all stars. The Sun is composed almost entirely of hydrogen and helium gas. Multimillion-degree temperatures in its dense core sustain nuclear fusion, providing the energy source for sunlight. The surface of the Sun is marked by colossal magnetic storms. The Sun’s gravity holds in orbit a family of planets, moons, asteroids, and comets - the solar system.
Subtopic: The Sun
Keywords: Astrophysics, Helium, Hydrogen, Nuclear fusion, Solar system, Sun