Question

I read this, "Nebulae form when stars die, when the end comes for our sun, for example, its outer layers will heat, swell, and eventually blow off. The hot, dead core will create a glowing nebula, which will, in turn, become a nursery for new stars" and also "death of nearby stars, triggered the birth of our planets and other contents of the galaxy"

Doubts:
1) they've mentioned that new STARS(more than one star) are formed after a star dies, does that mean, the size of the new stars is smaller than the original one, cause multiple stars are going to be formed from one star? and does it mean every time a star dies, the new stars become smaller and smaller?
2)they have mentioned that the death of nearby stars also gives birth to planets and other content in the galaxy, how is that possible?

Answer 1

Answer:When the helium fuel runs out, the core will expand and cool. The upper layers will expand and eject material that will collect around the dying star to form a planetary nebula. Finally, the core will cool into a white dwarf and then eventually into a black dwarf.

Explanation: