Scientists estimate that there are trillions of galaxies in the entire Universe, but some of them are more exciting than the rest. Galaxies needed a few hundred million years to form, and the very first such kind of majestic cosmic structure that formed also gets the prize of the farthest galaxy from the observable Universe.
The more you look far away into the depths of the Cosmos with powerful telescopes, the more you look back in time. This phenomenon happens because of the fact that the distance to a certain space object is too far away even for light to travel it during a short span. In other words, we see a space object as it was when the light left it. If, for instance, we’re looking at a star located at about 100 light-years away from us, it also means that we’re seeing it as it was during The First World War, about a century ago.
GN-z11 becomes the oldest and farthest galaxy ever discovered
Astronomers led by Nobunari Kashikawa, who is a professor in the astronomy department at the University of Tokyo, are declaring GN-z11 the farthest and oldest galaxy ever discovered. They had been analyzing data collected by the Hubble Space Telescope. The galaxy formed during a time when the Universe was ‘only’ 400 million years old. Therefore, the GN-z11 galaxy is 13.4 billion years old, almost as old as the Universe itself.
As for the distance between the galaxy and Earth, Kashikawa declared:
From previous studies, the galaxy GN-z11 seems to be the farthest detectable galaxy from us, at 13.4 billion light-years, or 134 nonillion kilometers (that’s 134 followed by 30 zeros),
But measuring and verifying such a distance is not an easy task.
The scientific team had been studying the galaxy’s redshift to determine how far away the object is from Earth. They focused on seeing how much the light has stretched out or shifted towards the spectrum’s red end. The scientists also looked at the emission lines of GN-z11, and they were able in the end to understand how much the light traveled to get to us from the galaxy. Thus, they could figure out the distance from Earth. Space.com shows us the galaxy in the following image:
Credit for the image goes to NASA, ESA, P. Oesch (Yale University), G. Brammer (STScI), P. van Dokkum (Yale University), and G. Illingworth (University of California, Santa Cruz)
Kashikawa explains more:
We looked at ultraviolet light specifically, as that is the area of the electromagnetic spectrum we expected to find the redshifted chemical signatures.
But even so, things are a little more complicated than they look.
Observable Universe doesn’t mean the entire Universe
The term ‘observable Universe’ is generally used as a synonym for ‘Universe’, which is wrong. Finding the oldest galaxy from the observable Universe doesn’t automatically mean that the object is the oldest galaxy from the whole Universe itself. The observable Universe is just the portion of spacetime from where the light had enough time to reach our planet during the 13.8 billion years. The entire Universe could be even one million times bigger than just the observable Universe. There’s no known possibility to see beyond the boundaries of the observable Universe besides opting for the biggest virtue of them all: have patience. But unfortunately, time is not on our side on this one, unless technology will provide us with the secret for eternal youth in the near future.
The new study was published in the journal Nature Astronomy.