what is a star, why does it burn?

Answer 1

A star is a ball of gas, mostly hydrogen. At the core, the pressure and temperature are high enough to cause fusion of hydrogen atoms into helium atoms, a process that produces energy (like the process in a hydrogen bomb, but continuous). That energy is the "burning" of the star.

Answer 2

A star (that includes our nearest star Sun) is a huge mass of hydrogen, helium and other gases, which got heated to an extremely high temperature by the gravitational pull towards the centre of the mass and thus a nuclear fusion reaction is taking place. Thus a star is a nuclear fusion reactor where hydrogen is getting converted into helium and in that process, energy is being released. The hot gases tend to expand outward but are constrained by the gravity and thus the size of the star remains constant in this phase of its life. Once the fuel is exhausted, the star cools down and shrinks. Due to the tremondous pressure of gravity, fresh nuclear reactions may start and the star may even explode. What happens depends more on the mass of the star than anything else.

Answer 3

A star is a huge mass of gas, mostly hydrogen.

Technically it doesn't burn! Burning is the chemical reaction of an element with oxygen,producing infra-red radiation (heat) and visible light. This does not happen in a star.

A star is a massive atomic fusion plant. Hydrogen combines to form Helium, giving off radiation. Some of that radiation becomes visible light and some of it infra-red radiation (heat).

So the effectis that a star appears to burn, but the mechanism is completely different.

Answer 4

A star is a ball of gas held together by its own gravity. The force of gravity is continually trying to cause the star to collapse. This is counteracted by the pressure of hot gas and/or radiation in the star's interior. This is called hydrostatic support. During most of the lifetime of a star, the interior heat and radiation is provided by nuclear reactions near the center; this is phase of the star's life is called the main sequence. Before and after the main sequence, the heat sources differ slightly: before the main sequence the star is contracting, and is not yet hot nor dense enough in the interior for the nuclear reactions to begin. During this phase, hydrostatic support is provided by the heat generated during contraction; after the main sequence, most of the nuclear fuel in the center has been used up. The star now requires a series of less efficient nuclear reactions for internal heat, before finally collapsing when these no longer generate sufficient heat to support the star against its own gravity.

Answer 5

star is a gaseous ball which created by collapsing interstellar clouds it does not burn (like wood or something similar) because of the high grade of temperature the atoms starts to compose with each other and make the heavier atoms which we call it fusion the fusion emits high energy so it makes an star bright so we think its just burning

Answer 6

A star is a very large object with enough mass to undergo nuclear fusion. A star doesn't burn. It creates heat through nuclear fusion.

Answer 7

In a nut shell it is hydrogen gasses mixed with assorted elements compressed to the point of nuclear ignition, and burns by fusion of hydrogen into helium

Answer 8

Our sun is a star.