system
Given the following post, respond as if you're commenting on Reddit:
human
[Astronomy] Do we know enough about the heavy metal output of supernovae to speculate as to what the mass of the first generation of stars was? What do we know about the first stars?
gpt
The heavy metal output of supernovae doesn't tell us much about the mass of the first stars, because the lifetime of the highest mass stars is only around 3-10 million years. Thus, there have been thousands of generations of stars since the Big Bang. We would need to observe extremely old stars to detect the influence of the very first stars- scientists are trying to do this, but don't get your hopes up.

The big difference between the first stars and later stars is that the first stars don't have any elements larger than Hydrogen and Helium in them, which makes them relatively transparent to light. (Edit: this means that the star is less (but still very) opaque not that it is actually invisible.)

 In order for light to interact strongly with Hydrogen and Helium it needs to have the same frequency as one of its electron transitions (or ionizations), which is unlikely. Adding heavier elements greatly increases the probability that the light will be absorbed. As a result, the radiation pressure has a much stronger effect on modern stars, which limits their maximum mass and makes a collapsing cloud more likely to fragment  to make small stars. 

We think that the first stars may have all had masses above 100 solar masses, so they would have died quickly by going supernova. But we're not sure - the first stars might also have had small masses due to other effects.