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Aug 23, 1998 · star, any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. Of the tens of billions of trillions of stars composing the observable universe, only a very small percentage are visible to the naked eye. Many stars occur in pairs, multiple systems, or star clusters.
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. Birth. Stars form in large clouds of gas and dust called molecular clouds.
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.
Aug 23, 1998 · stellar evolution. Throughout the Milky Way Galaxy (and even near the Sun itself), astronomers have discovered stars that are well evolved or even approaching extinction, or both, as well as occasional stars that must be very young or still in the process of formation.
Sep 26, 2022 · Stars are giant, luminous spheres of plasma. There are billions of them — including our own sun — in the Milky Way galaxy. And there are billions of galaxies in the universe. So far, we...
The universe’s stars range in brightness, size, color, and behavior. Some types change into others very quickly, while others stay relatively unchanged over trillions of years.
Mar 20, 2019 · Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores.
Stars are spherical balls of hot, ionized gas (plasma) held together by their own gravity. Stars are the most fundamental building blocks of our universe.
Groups of stars make up galaxies, while planets and ultimately life arise around stars. Although stars have been the main topic of astronomy for thousands of years, we have begun to understand them in detail only in recent times through the advent of powerful telescopes and computers.
Discover the wonders of the night sky with NASA's interactive skymap. Learn about stars, planets, constellations and more with a click of your mouse.