what happens to Sun if it does not have any hydrogen?

Answer 1

The Sun fuses hydrogen to helium in an atomic reaction similar to a hydrogen bomb, this reaction gives off energy and hence provides us with a lot radiant energy, Most astronomers believe that the sun has been “turned on” for about 4.5 billion years.

As the sun gets older, it will continue to fuse hydrogen in its core, scientists estimate that there is enough hydrogen fuel to continue this process for another 4 billion years or so, then the fun starts….

Once the majority of the sun’s hydrogen is turned into helium, it stops fusing hydrogen and loses its ability to combat gravity, the sun will begin to compress under its own weight. The higher pressures and temperatures at the sun’s core will cause helium to begin to fuse into carbon in a similar process to the hydrogen fusion, this too balances out the gravity and the sun will continue to shine, but the process of fusing helium gives off more energy than the fusing of hydrogen. This additional energy streaming out of the core radiates through the “envelope”, the layers outside the core. This very high energy into the envelope heats up the envelope causing the envelope expand greatly to hundreds of times its original size.

The part that can be seen (the envelope) is much cooler than the young sun was and it is red in color, the sun has become a red giant star.

Even though the red envelope is cooler than the young sun it is still very hot, about 5000° Fahrenheit! Unfortunately, for any life on planets in the inner solar system, the red giant sun's envelope will expand to engulf all the way out past Earth and Mars. All the oceans will be evaporated away and in fact the Earth's atmosphere will be blown into space. The engulfed planets will, obivously, be uninhabitable.

Answer 2

The fusion reaction producing heat, light, and radiation in the Sun is presently using Hydrogen and fusing it into Helium at tremendous temperature and pressure.

When the supplies of Hydrogen diminish significantly, since the pressure and heat are still there, the fuel will become a mix of Hydrogen and Helium, and finally Helium only. This phase marks the begining of the demise of the Sun and is forecasted to begin about five billion years from now.

Answer 3

As the fuel burns out the Sun will first expand to a red giant, then collapse under it's own weight to become either a white dwarf or a neutron star depending upon how much mass is left when it collapses.

Answer 4

well it would not have formed in the first place. and right now it is mostly hydrogen. so if it just lost all of that hydrogen it wouldnt have enough mass to form helium and it would simply become a large failed star.

Answer 5

we have a backup fuel... Helium.

when the Sun runs out of Hydrogen, it will burn Helium for a while...

Its not massive enough to go heavier than that.

Answer 6

Once it runs out of H to convert, it will either become and black dwarf or a white dwarf. Same chance of either of these coming true. It will expand, the gravitational pull will increase, and then it will implode.

Answer 7

then it will stop burning.