Star | Definition, Light, Names, & Facts | Britannica
5 天之前 · What is a star? A star is any massive self-luminous celestial body of derived from its internal energy sources. Of the tens of billions of trillions of stars in the observable universe, only a very small percentage are visible to the naked eye. Why do stars twinkle?
Star - Wikipedia
A star is a luminous spheroid of plasma held together by self-gravity. [1] The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night; their immense distances from Earth make them appear as fixed points of light.
Stars - NASA Science
Stars are giant balls of hot gas – mostly hydrogen, with some helium and small amounts of other elements. Every star has its own life cycle, ranging from a few million to trillions of years, and its properties change as it ages. Stars form in large clouds of gas and dust called molecular clouds.
What Is a Star? | Types of Stars - Sky & Telescope
2014年7月15日 · A star is a luminous ball of gas, mostly hydrogen and helium, held together by its own gravity. Nuclear fusion reactions in its core support the star against gravity and produce photons and heat, as well as small amounts of heavier elements.
Star - Simple English Wikipedia, the free encyclopedia
A star is a very large ball of bright, glowing, hot matter in space. That matter is called plasma. Stars are held together by gravity. They emit light because they are very hot. The Sun is an …
Stars—facts and information - National Geographic
2019年3月20日 · Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Aside from our sun, the dots of light we...
Star Facts - Interesting Facts about Stars - Space Facts
Stars are luminous spheres made of plasma – a superheated gas threaded with a magnetic field. They are made mostly of hydrogen, which stars fuse in their cores. That process releases energy, which pushes against the weight of the outer layers of the star and keeps it stable.
What is a star? | Space
2022年1月28日 · It's easy enough to say what a star is: one of those bright pointy things that twinkle in the night sky. But the actual definition of a star is as rich and colorful as the...
What are stars? - BBC Sky at Night Magazine
Stars are glowing celestial bodies consisting of mostly hydrogen (90%) and helium (10%) that can be seen in the night sky because nuclear reactions at their core give off heat and light energy. …
What is a Star? - General Astronomy - Telescope Live Community
2023年9月19日 · A star is a very hot and luminous object, so luminous that we can see some of them which are thousands of lightyears away with our naked eye. It is powered by nuclear fusion, a process that occurs in its core.