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XzAeRosho | 1 year ago

>The presence of oxygen so early in the life of this galaxy is a surprise and suggests that multiple generations of very massive stars had already lived their lives before we observed the galaxy.

For some reason this quote blew me away. It's just so hard to comprehend the timescales and vastness of the universe.

discuss

order

astroH|1 year ago

Multiple generations is perhaps an overstatement. The first oxygen in the Universe came from what we call Population III stars which is the first generation of stars to form after the Big Bang and what separates these from other stellar populations is that they do not have elements heavier than hydrogen or helium (except for minuscule traces left over from the Big Bang but these are insignificant). Now we don't know much about Population III stars but many models predict they are massive and when they die, can release 60 times the mass of our sun in the form of oxygen. That's really a lot of oxygen so you don't need too many of these to go off to pollute the early Universe and probably one of the reasons why we haven't yet found Population III stars.

astro-throw|1 year ago

The word "generation" isn't really a thing in astronomy jargon. "Population III" is a population, and it includes stars formed after some supernovae, up to the point where the metals % gets high enough to be Population II.

malfist|1 year ago

Big stars burn hot and fast, the more mass, the shorter their lives

vlovich123|1 year ago

It's interesting that [1] has a diagram showing that in 2022 the NASA diagram claimed that stars & galaxies formed 400M years ago so this feels like a big shift to having a massive galaxy already at 300M with data suggesting it's formed after several generations of stars.

> All of these observations, together, tell us that JADES-GS-z14-0 is not like the types of galaxies that have been predicted by theoretical models and computer simulations to exist in the very early universe

This is exciting. Maybe our understanding of the Big Bang is extremely flawed & this data is just the first inklings that we have to reimagine what we know about it?

dylan604|1 year ago

> formed 400M years ago

do you mean formed 400M years after the big bang instead of 400M years ago from today? That's like yesterday to the Universe.

colechristensen|1 year ago

Very large stars live very short lives.

Our star will live 10 billion years, the smallest stars will last trillions of years, the largest stars live less than 10 million years and some very early stars broke the models for how big they were and maybe lived much less long.

What happens is their cores go through stages of fusing an element until they run out, gravity takes over and shrinks the core until the next element ignites, fuses, and runs out, down to iron. At one of those stages the collapse triggers a supernova (or one of the class of ways a star can die) instead.

bmitc|1 year ago

The scale of both time and space are the least confusing things in our universe, to me at least.