Oct 22, 2024 · Astronomers call stars that are stably undergoing nuclear fusion of hydrogen into helium main sequence star s.This is the longest phase of a star’s life. The star’s luminosity, size, and temperature will slowly change over millions or billions of years during this phase.

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.

Jan 21, 2025 · Star, any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. This article describes the properties and evolution of individual stars. Included in the discussion are the sizes, energetics, temperatures, masses, and chemical compositions of stars.

Jan 22, 2025 · A rare breed of star recently discovered by the Hubble Space Telescope spins faster by feeding on its stellar siblings. The Hubble Space Telescope has discovered a rare "blue lurker" star that has ...

Oct 22, 2024 · When a main sequence star less than eight times the Sun’s mass runs out of hydrogen in its core, it starts to collapse because the energy produced by fusion is the only force fighting gravity’s tendency to pull matter together.

Four Planets in One View! Each evening this month, enjoy a sweeping view of four bright planets at once. Also look for a close approach of Venus and Saturn, Mars occulted by the Moon, and meteors! Cue the planet parade, Saturn and Venus cross paths, Mars expresses its opposition, and the outlook for ...

Feb 2, 2023 · What is a Star? A star is a giant sphere of extremely hot, luminous gas (mostly hydrogen and helium) held together by gravity. A few examples of well-known stars are Pollux, Sirius, Vega, Polaris, and our own Sun. Stars are essentially the building blocks of galaxies and are the source of all the heavier elements.

Explore the night sky with NASA's interactive star map and discover constellations, planets, and more.

Jul 15, 2014 · A star’s color relies on its temperature: hotter stars emit bluer light and cooler stars emit redder light. Temperature is also correlated to mass.

Is there a meteor shower tonight? Find out how and where to see shooting stars in 2025. What time is the meteor shower most visible?