The things that the JWST is discovering are just mind-boggling. It was long suspected that the first stars were gigantic and extremely luminous (and also, for that reason, relatively short-lived) and these observations offer tangible albeit indirect insights into the earliest times of creation. This early galaxy is so old, and the early universe so small at the time, that it would be nearly 10 billion years before our sun and planets began to form, and in a sense the space itself that we inhabit did not yet exist.
It’s a mind bending experience to think about how the expansion of the universe means that we are outside of where the light from these stars used to be but now to see that light we have to look further out. (Does what I’ve written even make sense?)
I know that words like “where” make much less sense when it’s space time itself that is expanding.
James Webb Tekescope: “ooo - you stink!”
JWT data reveals a new record holder for the most distant galaxy. The submission to the Open Journal of Astrophysics speculates that MoM-z14 “hint[s] at an abundance pattern similar to local globular clusters that may have once hosted luminous supermassive stars. Since this abundance pattern is also common among the most ancient stars born in the Milky Way, we may be directly witnessing the formation of such stars in dense clusters, connecting galaxy evolution across the entire sweep of cosmic time.”
Neat. Though I’m somewhat surprised at the metallicity of these old galaxies. I.e., I wasn’t expecting spectral lines from elements beyond lithium.
I did a little more reading and it looks like Population III stars–that is, the very first generation of stars and thus virtually absent of metals–haven’t been observed yet by anyone, but it is hoped that the JWST will spot some eventually.
Is JWST powerful enough to spot individual stars that far back? I thought we were talking galaxies and with those it doesn’t take many odd-balls to contaminate the spectra of the rest.
Not sure. Maybe it could spot individual stars that have been ejected from a galaxy and where the light isn’t mixed up.
I was thinking of not just the first galaxies, but the first few million years of the first galaxies, before any of the Pop III stars had gone supernova and spread metals everywhere. Not sure how long they’re supposed to last. Wikipedia suggests we don’t even know how big they should be.
Guess we should let the experts figure it out.
I found this:
The first Population III stars are predicted to form in minihaloes at z ≈ 10-30. The James Webb Space Telescope (JWST), tentatively scheduled for launch in 2018, will probably be able to detect some of the first galaxies, but whether it will also be able to detect the first stars remains more doubtful. Here, we explore the prospects of detecting an isolated Population III star or a small cluster of Population III stars down to z = 2 in either lensed or unlensed fields. Our calculations are based on realistic stellar atmospheres and take into account the potential flux contribution from the surrounding H II region. We find that unlensed Population III stars are beyond the reach of JWST, and that even lensed Population III stars will be extremely difficult to detect. However, the main problem with the latter approach is not necessarily that the lensed stars are too faint, but that their surface number densities are too low. To detect even one 60 M⊙ Population III star when pointing JWST through the galaxy cluster MACS J0717.5+3745, the lensing cluster with the largest Einstein radius detected so far, the cosmic star formation rate of Population III stars would need to be approximately an order of magnitude higher than predicted by the most optimistic current models
Gravitational lensing can increase the amount of light that reaches Earth. But there may not be enough of them to find.