Star
lastmod 2015-06-11created 2015-06-111 edits
A star, or fixed star (恒星, fixed star), is a massive, luminous spherical celestial body of plasma (ionized gas) held together by gravity. It is commonly called a star. The star nearest to Earth is the Sun, which supplies most of the energy on Earth. Other stars can be seen from Earth in the night sky, but during the day they are hidden by sunlight. A star shines because the energy released by nuclear fusion reactions at its core passes through its interior and is emitted. Almost all matter heavier than hydrogen and helium was created inside stars.