As the Sun loose mass continually ,how much will it shink ultimatelly? At what limit?

Answer 1

My understanding is that, as the hydrogen of the sun undergoes nuclear fusion to become helium, which fuses to beome denser elements, which gravitate to the core of the sun, and cools the fusion reactor, its fusion reactions will become more intense and will cause the hydrogen and helium to form into an atmosphere which might wind up engulfing the inner planets, including Mars, until the fusion reactions slow down enough to where the hydrogen and helium atmospheres condense again, and when it reaches the critical mass needed for a reaction of nuclear fission, it will go supernova, and will expell dense matter all the way out beyond the orbit of Neptune, which is how so many comets and the Kuiper asteroid belt likely came into existence.

The more matter it ejects into orbit around it, it will eventually shrink and keep on shrinking in size, but eventually, it will reach a minimum size, after which time it will again resume amassing matter that falls out of orbit, and will again increase in size...

and so, on and so on..

As to your question of how much... there are too many unprovable theories about that, and what will be the limits, the jury is still out about that as well.

Answer 2

The loss of mass from the Sun is very small. The Sun is about 4.5 billion years old. Over this lifetime, it has lost about 0.008% to mass-energy conversion, and about 0.001% to solar wind.

Over the next 4 billion years, it should lose about 0.05% of its mass, or maybe 0.1%. This is before the Red Giant stage. When the sun becomes a red giant, it could lose about 7% to 10% of its mass.

After another 4 billion years or so, it will throw off a "planetary nebula", losing up to 50% of its mass. Our sun is NOT the type that goes supernova.

Answer 3

it's my understanding that as the sun begins to die, it will actually expand far beyond the reaches of earth & mars, before finally contracting down to the size of a white dwarf star.