Why Do Some Stars Grow So Massive?

[mjacobsca]

Why are some stars so much more massive than others? Eta Carinae and The Pistol Star are 100X more massive than the Sun. When stars are forming, doesn't hydrogen fusion begin at about the same mass and density for all stars? Or does chemical composition and rotational velocity of the nebular gas cloud contribute to such huge variations? I assume Eta Carinae had a larger amount of available gas in the first place. But if fusion can start when the star has accumulated smaller mass like our Sun, why doesn't it ignite and push the remaining gas away before growing larger? Can it accumulate more mass from the gas cloud after igniting? I also assume collisions with other stars are rare enough not to be considered.

 

[turbo]

I suggest that you Google "stellar accretion rates" and start browsing the papers and following the citations in them.

 

[Lost in Space]

Why are some stars so much more massive than others? Eta Carinae and The Pistol Star are 100X more massive than the Sun. When stars are forming, doesn't hydrogen fusion begin at about the same mass and density for all stars? Or does chemical composition and rotational velocity of the nebular gas cloud contribute to such huge variations? I assume Eta Carinae had a larger amount of available gas in the first place. But if fusion can start when the star has accumulated smaller mass like our Sun, why doesn't it ignite and push the remaining gas away before growing larger? Can it accumulate more mass from the gas cloud after igniting? I also assume collisions with other stars are rare enough not to be considered.

From what I understand, red giants are really long lived stars and much less dense and cooler than the short-lived massive hot stars that produce the higher elements in nuclear fusion and distribute them by becoming supernovae.

 

[Misericorde]

The honest answer is that some stars (not 100x) such as hypergiants, much like supermassive black holes, don't have one clear explanation. Stellar formation isn't exactly a mystery, but it's an ongoing realm of study with unanswered questions.