He was launched to look back at the beginning of time and take pictures of the first stars to shine in space.
Now, in the latest of its many exciting discoveries thus far, the James Webb Space Telescope (JWST) has discovered one of the oldest galaxies in the universe.
Formed just 390 million years after the Big Bang, it has been named Maisie’s galaxy after the daughter of the astronomer who first saw it on her birthday.
The scientists say it is one of the first four confirmed galaxies ever seen, though they are currently evaluating another 10 that could be from an era even earlier than Maisie’s.
“What’s exciting about Maisie’s galaxy is that it was one of the first distant galaxies identified by JWST, and of that set, it’s the first to be confirmed spectroscopically,” said Steven Finkelstein, who led the University of Texas-led research. in Austin.
The beginning of time: NASA’s James Webb telescope has discovered one of the oldest galaxies in the universe. It has been named Maisie’s galaxy, after the daughter of the astronomer who discovered it.
Instruments on the James Webb Space Telescope
NIR camera (Near InfraRed Camera) an infrared camera from the edge of the visible to the near infrared
NIRSpec (Near InfraRed Spectrograph) will also perform spectroscopy in the same wavelength range.
MIRI (Mid Infrared Instrument) will measure the mid to long infrared wavelength range from 5 to 27 micrometers.
FGS/NIRISS (Fine Orientation Sensor, Near Infrared Imager, and Slitless Spectrograph), is used to stabilize the observatory’s line of sight during science observations.
The way astronomers determine the age of a galaxy is complicated.
It involves calculating when the light left an object, which is calculated by measuring the redshift of the galaxy.
This is the amount that its color has changed due to its movement away from Earth.
Therefore, because we live in an expanding universe, the greater the redshift of an object, the older it is.
When it came time to estimate the age of Maisie’s galaxy, Finkelstein and his team first based the redshift on photometry, which is the brightness of light in images using a small number of broad-frequency filters.
This gave them a rough idea, but to come up with a more precise estimate they needed to request new measurements from JWST’s spectroscopic instrument, NIRSpec (Near InfraRed Spectrograph).
This splits an object’s light into many different narrow frequencies to more accurately identify its chemical composition, heat output, intrinsic brightness, and relative motion.
According to this latest spectroscopic analysis, Maisie’s galaxy has a redshift of z=11.4.
The researchers also studied a galaxy called CEERS-93316, which was originally estimated to have formed just 250 million years after the Big Bang.
The researchers also studied a galaxy called CEERS-93316 (pictured), which was originally estimated to have formed just 250 million years after the Big Bang. However, it later emerged that scientists had been trapped by its blue tint, and it actually formed a billion years after the creation of the universe.
However, after carrying out the follow-up analysis, it emerged that CEERS-93316 had a more modest redshift of z=4.9, which is about a billion years after the creation of the universe.
The reason the initial calculation was wrong was because scientists later discovered that the hot gas in CEERS-93316 gave off so much light in a few narrow frequency bands associated with oxygen and hydrogen that it made the galaxy appear much bluer than it actually was.
This bluer tint mimicked the signature astronomers expected to see in very early galaxies.
However, it is actually a quirk. from the photometric method that occurs only for objects with redshifts around 4.9.
“This was a weird type of case,” Finkelstein said.
“Of the many dozens of high redshift candidates that have been observed spectroscopically, this is the only instance where the true redshift is much less than our initial assumption.”
The galaxy not only looked unnaturally blue, but was also found to be much brighter than current models predict for galaxies that formed so early in the universe.
“It would have been really challenging to explain how the universe could create such a massive galaxy so soon,” Finkelstein said.
“So I think this was probably always the most likely outcome, because it was very extreme, very bright, with apparently such a high redshift.”
JWST cost $10bn (£7.4bn) to build and launched in December 2021 from Europa’s spaceport near Kourou, French Guiana.
Their ultimate goal is to look further back in time 13.5 billion years to a point within 100-200 million years of the Big Bang.
Maisie’s discovery of the galaxy has been revealed in the journal. Nature.
The James Webb Telescope: NASA’s $10 billion telescope is designed to detect light from the first stars and galaxies.
The James Webb Telescope has been described as a ‘time machine’ that could help unlock the secrets of our universe.
The telescope will be used to observe the first galaxies born in the early universe more than 13.5 billion years ago and to observe the sources of stars, exoplanets and even the moons and planets of our solar system.
The big telescope, which has already cost more than $7bn (£5bn), is seen as a successor to the orbiting Hubble Space Telescope.
The James Webb Telescope and most of its instruments have an operating temperature of about 40 Kelvin, about minus 387 Fahrenheit (minus 233 Celsius).
It is the largest and most powerful orbiting space telescope in the world, capable of looking back 100-200 million years after the Big Bang.
The orbiting infrared observatory is designed to be about 100 times more powerful than its predecessor, the Hubble Space Telescope.
NASA likes to think of James Webb as a successor to Hubble rather than a replacement, since the two will be working in tandem for a while.
The Hubble Telescope was launched on April 24, 1990 via the Space Shuttle Discovery from the Kennedy Space Center in Florida.
It circles the Earth at a speed of approximately 17,000 mph (27,300 kph) in a low Earth orbit at approximately 340 mile altitude.