The James Webb Space Telescope has discovered five of the earliest galaxies in the universe among those known to astronomers. These galaxies existed just 200 million years after the Big Bang, meaning they are 90 million years younger than the previous record holder. The study has been published on the preprint server arXiv, according to Live Science.
The Webb telescope has broken its own record for identifying the earliest galaxies in the universe known to scientists. Five new galaxies have been found, which are still candidates for this title, as further observations are needed to confirm this fact.
The earliest galaxies observed by the Webb telescope existed during the very early stages of the universe's history, specifically 200 million years after the Big Bang. Prior to this, the earliest known galaxy was JADES-GS-z14-0, which existed 290 million years after the universe's birth. The new astronomical objects are approximately 13.6 billion years old, while the universe itself is 13.8 billion years old.
Although the light from the five earliest galaxies has traveled to us for 13.6 billion years, these objects are currently situated 13.6 billion light-years away, as the universe has significantly expanded since then. However, it is still challenging to determine their exact distance.
According to scientists, some of the very first galaxies formed in the universe have been discovered, but there are likely many more yet to be found. Interestingly, all five of these earliest galaxies are located relatively close to each other in a single region of space.
So far, astronomers have not been able to determine the exact size and mass of these galaxies, as this is quite difficult. The reason is that the earliest galaxies are extremely faint, but they were detected thanks to the infrared instruments of the Webb telescope.
Astronomers also had to use gravitational lensing to detect the five ancient astronomical objects. According to Einstein's theory of relativity, gravity is a curvature and distortion of space-time in the presence of matter and energy. The warped space determines how energy and matter move. This means that even if light travels in a straight line, it can be bent and magnified by gravity. Ideally, this should involve very strong gravity, which is provided by a galaxy or a cluster of galaxies.
The galaxy that acted as a gravitational lens for the light from the earliest galaxies was Abell S1063, located much closer to the Webb telescope. The gravity of this galaxy significantly amplified the light from these very distant galaxies, making them visible to the telescope.
If astronomers can confirm their preliminary findings, these earliest galaxies will help scientists test theories about the formation of such objects in the early universe, as well as theories concerning how matter first began to coalesce into large structures in the cosmos.