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 …

5 days ago · A star is 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 in the observable universe, …

May 2, 2025 · A star’s gas provides its fuel, and its mass determines how rapidly it runs through its supply, with lower-mass stars burning longer, dimmer, and cooler than very massive stars.

These large, swelling stars are known as red giants. But there are different ways a star’s life can end, and its fate depends on how massive the star is.

May 8, 2025 · How does a star work? How do they form, live, and eventually die? Learn more about these distant objects and their major importance in the universe.

Oct 22, 2025 · Main Sequence: The protostar continues to collapse until nuclear fusion begins in its core, leading to the formation of a stable star. This stage is known as the main sequence, where the …

4 days ago · The simplest way to describe a star is that it is a great ball of fire, but it is more complicated than that. A star is a giant ball of hydrogen turning into helium through nuclear fusion.

Dec 4, 2025 · Star - Formation, Evolution, Lifecycle: Throughout the Milky Way Galaxy (and even near the Sun itself), astronomers have discovered stars that are well evolved or even approaching …

The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its …

The amount of material in a star (its mass) is so huge that a nuclear reaction called nuclear fusion goes on inside it. This reaction changes hydrogen to helium and gives off heat.