Were the first stars much larger and shorter-lived than our sun?

[pforeman]

Looking at the huge clumps of higher elements (carbon silicon iron etc) present in our solar system, it seams as though only a few tens of billions of years would not be enough time to make all of the higher elements in the quantities we see today with stars like our sun that last billions of years.
Were the majority of the first stars ultra large which lasted only millions of years?
How soon after the big bang did these first stars form?
Did the early (smaller) universe contain much larger stars that were much closer to each other (and much closer galaxies) that enabled the "sharing" of these newly formed higher elements?
Would it be correct to think that most of these higher elements found on Earth were formed in the first couple of billion years of the universe?
Thanks for your help,
Paul

 

[SteamKing]

A large star 25 times as massive as the sun can spend as little as 6.4 million years on the main sequence, which is that portion in the life of a star where its energy comes from fusing hydrogen. At each stage beyond the main sequence (for example, burning helium, burning carbon, etc.), the duration of these stages is progressively shorter. The final stage of stellar evolution, just before core collapse, lasts only about 24 hours.

http://www.uni.edu/morgans/astro/course/Notes/section2/new7.html

There is evidence that the first stars could be truly massive in size, on the order of 100 solar masses, which would also imply a much shorter life before the formation of the supernova which destroyed those stars. The total lifespan of these massive stars would be but a brief instant compared to the current age of the universe.

This article from Scientific American answers most of the questions you have about stellar formation and galactic evolution in the early life of the universe:

http://www.scientificamerican.com/article/the-first-stars-in-the-un/

 

[Benit13]

In addition to SteamKing's response, early stars with very low metallicity generally need to burn hydrogen at a higher core temperature than younger, higher metallicity stars. This is because there will be very little carbon, nitrogen and oxygen for the CNO cycle, which is the dominant hydrogen forming nucleosynthesis process in massive stars and a small process in lower mass stars. Oddly enough then, early stars will compress slightly more under gravity to achieve the higher temperature and therefore have smaller radii than their higher metallicity equivalents. So they may be more massive, but certainly not larger!

But yeah, there were definitely more massive stars in the early universe than now because of their relatively short evolution times and the fact that star formation rates tend to decline over time. Initial mass functions imply that there are always more lower mass stars than massive stars (see for example Salpeter IMF as a start). As for sharing of elements, this is typically managed either by close binary systems with accretion or by star formation in a gas cloud that is polluted by the yields of previous stars, the latter being most important for the presence of metals in stars. I'm not sure whether there were more binary systems in the early universe or not.

 

[Chronos]

The lack of metallicity in the early universe allowed stars to become much more massive than at present. By some estimates, stars as large as 1000 solar mass could have been formed. Such stars, called population III stars, would have been very short lived and quickly pollute the universe with 'metals'. They may have formed as early as 100 million years after the BB. Steamking's SA reference covers this nicely.

 

[sardar]

The first stars were indeed much larger and shorter-lived than our sun. This is because they were formed in a very different environment than our sun. The early universe was much denser and hotter, allowing for the formation of larger stars with a shorter lifespan. These stars, known as Population III stars, were composed almost entirely of hydrogen and helium, with very little of the heavier elements present.

It is estimated that these first stars formed within the first few hundred million years after the Big Bang. This was a time when the universe was still expanding and galaxies were just starting to form. These early stars were crucial in the formation of the heavier elements that we see in our solar system today. Through processes such as nuclear fusion and supernova explosions, they created and dispersed these elements into the surrounding space.

The early universe did contain much larger stars that were closer together, as the distribution of matter was much more uniform at that time. This allowed for the sharing of newly formed elements between stars and galaxies, contributing to the abundance of these elements in our solar system.

It is difficult to say exactly when most of the higher elements found on Earth were formed, but it is likely that a significant portion were formed in the first couple of billion years of the universe. This is because the heavier elements take longer to form and were only present in small quantities in the early universe. As more stars formed and evolved, they were able to create and distribute larger amounts of these elements, ultimately leading to the diverse composition of our solar system.

Overall, the first stars played a crucial role in shaping the universe and creating the elements that make up our world today. While they may have been short-lived, their impact and legacy continue to be felt billions of years later.