Early Population III stars were characterized by extremely low metallicity, which necessitated their formation as much larger entities, often exceeding hundreds of solar masses. Metallicity influences stellar formation by affecting cooling processes; without metals, gas clouds remain hotter, leading to higher Jeans masses and consequently larger stars. The discussion raises questions about whether the relationship between metallicity and stellar mass is causal or merely correlational, suggesting other factors may also play a role. A referenced paper provides a comprehensive overview of these dynamics. Understanding the interplay between metallicity and stellar mass is crucial for astrophysical models of early star formation.
Early Population III stars in the universe were very metal poor if not metal free and were apparently required to be much larger than todays stars, up to hundreds of solar masses, to form. What does the metallicity have to do with this?
Metals can catalyze fusion, metals can emit light and reduce the pressure in gas clouds.
Put everything in a simulation, and you might get some estimate for stellar masses somehow - no idea how this works in detail.
Are you sure this is a causation rather than a correlation? Perhaps older stars were larger for some other reason? I can't see how metallicity would have THIS much of a drastic effect on stellar masses, I would suspect there has to be some other cause along with the metallicity.
I have no idea Matterwave. I've merely read that the reason super massive stars were the only ones that could form was because of metallicity. Or at least that was what I got from it.
Partial solar eclipse from Twizel, South Isl., New Zealand ...
almost missed it due to cloud, didnt see max at 0710 NZST as it went back into cloud.
20250922, 0701NZST
Canon 6D II 70-200mm @200mm,
F4, 100th sec, 1600ISO
Makeshift solar filter made out of solar eclipse sunglasses
This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed).
n.b. I start this...
Asteroid, Data - 1.2% risk of an impact on December 22, 2032. The estimated diameter is 55 m and an impact would likely release an energy of 8 megatons of TNT equivalent, although these numbers have a large uncertainty - it could also be 1 or 100 megatons.
Currently the object has level 3 on the Torino scale, the second-highest ever (after Apophis) and only the third object to exceed level 1. Most likely it will miss, and if it hits then most likely it'll hit an ocean and be harmless, but...