[ExI] How the James Webb telescope is reshaping cosmology

BillK pharos at gmail.com
Fri Dec 16 13:13:58 UTC 2022

How the James Webb telescope’s glances back in time are reshaping cosmology
Galaxies might have formed earlier and faster than previously thought.

By Lisa Grossman    16 Dec 2022

The telescope, also known as JWST, has confirmed extreme distances to
four galaxies, one of which sets a record for cosmic remoteness by
shining about 13.475 billion years ago.
Taken together, the new observations suggest galaxies formed earlier
and faster than previously thought. “We’re entering a new era,” says
astronomer Swara Ravindranath of the Space Telescope Science Institute
in Baltimore.
The previous distance record holder existed between 13.3 billion and
13.4 billion years ago, or about 400 million years after the Big Bang
(SN: 1/28/20). JWST confirmed the distance to that galaxy and came
back with three more whose light comes from as early as 325 million
years after the Big Bang.

The galaxies are also surprisingly pristine, chemically speaking,
lacking in elements heavier than hydrogen and helium.

“We don’t see that in the present-day universe,” says Ravindranath,
who was not involved in the new discovery. It could mean that not many
of the galaxies’ stars have died in supernova explosions that spread
heavy elements around the universe, which suggests the galaxies’
original stars were not extremely massive.

And the JWST is just getting started!


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