There is no oxygen in space and a fire needs oxygen to burn so how does the sun burn ?

Fusion does not require oxygen though oxygen can be fused as well as most other elements under certain conditions

The sun does not burn---Its so big that the hydrogen atoms in the center FUSED together----Releasing a tremendous amount of NUCLEAR energy and HEAT Essentially, it is a NUCLEAR fireball, a "hydrogen bomb" of sorts, but so big it's gravity holds it in check and keeps it from exploding outwards----and keeps on crunching those hydrogen atoms into Helium in the center and keeping it going.   Only when the hydrogen mass is reduced, in billions of years, will the gravity weaken and it will expand outward swallowing the orbit of EARTH.

The sun does not "burn".  The intense gravity forced two hydrogen atoms to combine causing the creation of an atom of helium.  The mass of helium is slightly less that the mass of two hydrogen atoms.  So some mass has "disappeared".  That small amount of "missing" mass was converted to energy.  That energy is the light you see coming from the sun.  So, nothing is burning.  Mass is being converted to energy while helium is being made from two hydrogens.  That is a fusion reaction. The fusing of two hydrogens into helium.

Exactly! I bet everything they tell us about Space is a lie, just like their lies about Earth's shape! There is probably plenty of Oxygen in the firmament! The Illuminati don't want us to reap the benefits!

Burning is chemistry.  The Sun does not engage in chemical reactions, and in fact is much too hot for any molecules to exist.  I had to memorize the Chandrasekhar equations in college astronomy which show how the Sun produces energy.  You asked for it:

let P be protons; N be neutrons; e for electrons; p for positrons; G for energy; -> symbolizes yields.

1)  P + P -> PN + p + G

2a) PN + P -> P2N +p + G

2b) PN + PN-> 2P2N + G

3) P2N + P -> 2P2N + G

the various p all meet a free e and both become G

This question was one of the great scientific mysteries of the 1800s and early 1900s. How could the Sun continue to shine energy onto Earth for billions of years? Thankfully, the mystery has been solved, employing nuclear Physics. The Sun radiates as a black body, and its energy comes from the thermonuclear fusion of Hydrogen to Helium. Look up "black body radiation" on wikipedia. 

Stars don't burn like a log in your fireplace - that's a chemical reaction.

Instead, elements in stars undergo *fusion* - the combining of lighter atoms into creating heavier ones. In the sun's case, four atoms of hydrogen are being combined to form a single atom of helium, billions of times each second... those four hydrogen atoms are being fused to form helium.So... you know the bombs dropped on Hiroshima and Nagasaki? Those were *fission* bombs - the splitting of very heavy atoms into lighter ones - Uranium and Plutonium, respectively. They leveled everything in a 5-block radius, and caused blast damage out to 3 miles.  Now - have you seen the videos of Hydrogen Bomb tests over the Bikini atoll? Those were *fusion* bombs, which were hundreds of times more powerful - they *erased* small islands, and left mile-wide craters on the ocean floor. This is the same process that the sun undergoes; and, the energy that results is what we feel and see as heat and light.

Fusion of helium from hydrogen atoms in the sun.

The problem arises from what sometimes you'd read or hear: Stars burn hydrogen, or, more specifically, called "Hydrogen burning". This is completely misleading.  Physicists prefer using this terminology instead of: Hydrogen nuclei (protons, that is) combine under a tremendous force that creates tunneling; and this will yield deuterium which with more other steps energy will be emitted and so on, they say Hydrogen burning. And it is obvious that they use this deceptive phrase only to those who know nothing about fusion reactions taking place in stars.

Really ?

The Sun doesn't burn. Therefore, it has no need for oxygen.

Duh !