- 4065 - EARLIEST
STARS- may have been
discovered? JWST may have succeeded in
one of the biggest goals in the entire field of astrophysics. If this is
eventually confirmed as the first true detection of a “Population III star”, it
unlocks a whole new universe of scientific exploration and discovery.
-
----------- 4065 - EARLIEST STARS- may have been discovered?
- The James Webb
Space Telescope (JWST) may have just found the first stars in the universe.
-
- Researchers call
them Population III (or Pop III) stars, because sometimes astronomers name
things in reverse for some reason. Pop III are the oldest stars, Pop II are in
the middle, and Pop I are the newest. Our Sun is a Pop I star.
-
- This has nothing
to do with how far along a star is in its individual life cycle. Think of it
more like generations. There were two
keys to this discovery. One was the simple power of JWST. Because light has a
finite speed, the further away you look, the further back in time you can see
-
- The team used the
telescope to spy on GN-z11, a bright, really-far-away galaxy, in the hopes of
getting a strong and clear spectrum from when the universe was only about 400
million years old, Today, it’s around
13.7 billion years old.
-
- The other is a
property of starts called metallicity, the amount of metals a star has.
Astronomers call anything heavier than hydrogen or helium a metal. So, in space
terms, metals are just any sufficiently heavy elements.
-
- The metals
contained within and burned by a star are how we categorize these celestial
furnaces into their respective populations. Pop I have the highest
metallicities, and Pop III have the lowest.
-
- Heavy elements, by
and large, are created by stars whether it be through fusion in their inner
layers or in the moments of intense heat when they go supernova. The Pop I
stars currently littering the universe were made from the debris left behind
when Pop II stars exploded. But Pop II stars had to get their start from older
stars, as they have more metals than would have been available just after the
Big Bang, but less than Pop I.
-
- If Pop II needed
more metals than the Big Bang could provide, they must have been forged in Pop
III stars. Pop III stars are believed to be made almost entirely of hydrogen
and helium, very low metallicity.
-
- They would have
been truly massive, and likely would not have lived very long before exploding in the supernovas that
researchers believe seeded the entire rest of the universe with metals.
-
- The researchers
looked at the halo of gas around the outskirts of the galaxy, where they
believe Pop III stars may have formed. In that region, they found a very strong
HeIIλ1640 spectral line, which shows up in a spectrum when helium is extremely
hot.
-
- There’s no metal
around it. Not like there would usually be if there was a higher-metallicity
star burning nearby. Something made helium incredibly hot without any metals
present, at long last, a Pop III star.
-
- There are
alternative propositions to what could have caused this HeIIλ1640 line. One of
these is the potential presence of an active galactic nucleus at the center of
the GN-z11 galaxy.
-
- There’s potential
here. Researchers may have succeeded in
one of the biggest goals in the entire field of astrophysics. If this is
eventually confirmed as the first true detection of a Population III star, it
unlocks a whole new universe of scientific exploration and discovery.
-
-
June 23, 2023 EARLIEST STARS-
may have been discovered? 4065
------------------------------------------------------------------------------------------
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------ “Jim Detrick” -----------
--------------------- ---
Friday, June 23, 2023
---------------------------------
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