This is an often misunderstood aspect of the sun. The sun doesn't need to pull oxygen into itself to burn. It just does a bit of fusion magic!
When a star is dense enough it starts to fuse Helium together through a process called the "triple alpha process"; which results in Carbon! From there it's pretty direct for the star to fuse one more Helium to the Carbon via stellar nucleosynthesis to create Oxygen!
So you see, the Sun doesn't need to draw Oxygen from space. It just makes its own!
This is an often misunderstood aspect of the sun. The sun doesn't need to pull oxygen into itself to burn. It just does a bit of fusion magic!
When a star is dense enough it starts to fuse Helium together through a process called the "triple alpha process"; which results in Carbon! From there it's pretty direct for the star to fuse one more Helium to the Carbon via stellar nucleosynthesis to create Oxygen!
So you see, the Sun doesn't need to draw Oxygen from space. It just makes its own!