If stars are created in nebulae. And nebulae are formed by a dying star exploding. Does that mean that star size on average will get gradually smaller as ‘big’ stars are transformed into millions of smaller stars?

Question

If stars are created in nebulae. And nebulae are formed by a dying star exploding. Does that mean that star size on average will get gradually smaller as ‘big’ stars are transformed into millions of smaller stars?

In: Planetary Science

Answer 1

The new stars that are formed can be big, medium or small depending on the amount of dust and gas they (re)gather during reformation.

The average size of stars is not expected to gradually decrease over time due to the cyclical nature of star formation and death. It pretty much remains the same.

The distribution of star sizes, known as the initial mass function (IMF), tends to follow a relatively consistent pattern, with many low-mass (small) stars and fewer high-mass (big) stars. This distribution is a result of the physical processes governing star formation and is observed to be roughly similar across different regions of our galaxy and others.

The new big stars can still form because the material from the exploded big star (supernova) as it spreads out into space and mixes with other gas and dust. If enough material gathers together in a dense enough region within a nebula, it can form a new big star.

Edit: To add, and this is not necessarily ELI5

The physical processes that govern star formation and the distribution of star sizes can be based on the amount of gas that collapses (comes together) due to gravity, the turbulence that distributes this gas unevenly, the size of fragments from the exploding star, the push from strong radiation and stellar winds from newly formed stars, the magnetic fields within the clouds, the creation of binary or multiple star systems where stars transfer mass onto other stars, etc.