- 4126 - OLDEST GALAXY -
looking back in time? Born
less than 400 million years after the Big Bang, 'Maisie's galaxy' is
officially one of the four oldest galaxies ever discovered. A fiery orange smudge representing Maisie's
galaxy, one of the earliest galaxies in the known universe.
-
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4126 - OLDEST GALAXY -
looking back in time?
-
- Astronomers using the James Webb Space
Telescope (JWST) have confirmed that a distant smudge of light named for a
lucky birthday girl on Earth is one of the earliest known galaxies in the
universe.
-
- The object, named "Maisie's
galaxy" in honor of lead researcher Steven Finkelstein's daughter, who was
celebrating her birthday when the object was discovered last year, began
emitting light more than 13 billion years ago, or roughly 390 million years
after the Big Bang.
-
- This age places Maisie's galaxy among the
four oldest galaxies in the universe that have had their ages confirmed by
spectroscopy, a technique that splits light into its component frequencies to
better reveal its brightness, heat and chemical composition.
-
- First detected in August 2022 during JWST's
debut season of observations, the distant object was presumed to be extremely
old based on its brightness and redshift, the degree to which light stretches
into redder wavelengths as it crosses the ever-expanding universe. Generally, a
greater redshift indicates an older, more distant light source.
-
- However, judging an object's redshift by
the brightness of its light alone can be deceptive, as different elements
within stars and galaxies emit light at different frequencies, some of which
can make an object appear older and farther away than it truly is. To see past
this cosmic mirage, astronomers use spectroscopy to separate starlight into its
various frequencies, revealing what it's really made of.
-
- Using the JWST's “Near Infrared
Spectrograph” Maisie's galaxy and CEERS-93316, another galaxy that was
discovered around the same time and was initially estimated to exist just 250
million years after the Big Bang.
-
- After splitting the galaxy's light, the
researchers found that globs of hot hydrogen and oxygen contained there were
emitting light so intensely that they made the whole galaxy appear bluer, and
hence older, than it actually was. The revised estimate puts CEERS-93316 at
about 1 billion years after the Big Bang knocking it firmly off the list of
oldest known galaxies.
-
- Maisie's galaxy joins a short list of four
other galaxies, also discovered and spectroscopically confirmed by the JWST,
that formed between 300 million and 500 million years after the beginning of
space-time as we know it.
-
-
August 23, 2023 OLDEST GALAXY -
looking back in time? 4126
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Wednesday, August 23, 2023 ---------------------------------
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