When the sun will die in another 7 billion years and turn into a planetary nebula, will there will be a new star?
That usually only happens with stars more massive than the sun (about 8-12x). It'll just shrink to a tiny brown dwarf star.
I wonder if this brown dwarf will accrete around jupiter or saturn as they will orbit inside the planetary nebula
In its late stages the sun will be a red giant with a radius around that of the earth's orbit. After it runs out of helium, the final collapse will be to a dwarf. It will be located (relative to the rest of the solar system) where it is now.
On this site it's written that in the case of a star like the sun the expansion will continue until the outer portions of the star float away from the central portion. This outer portion is referred to as a planetary nebula and it leaves behind the core which is referred to as a white dwarf. http://wind.cc.whecn.edu/~marquard/astronomy/sunlike.htm But when the sun reaches it's white dwarf stage, will it emit more heat or less heat than today?
Pluto2, the better question to ask is will it emit more or less light than it does today. The answer is that it will emit less light!
If our sun had the impact to generate another star, there would need to be nearby a huge cloud of hydrogen, and it would have to trigger the cloud to collapse.