Stars and galaxies are formed due to one of the four fundamental forces of nature: gravity. In fact, the other three forces have crucial roles as well. Not only that gravity keeps our feet to the ground and our food on the plates, it allows our existence in the first place. No stars means no planets to receive light and energy, and therefore no life can be possible.
While scientists believe that the first galaxies and stars started to illuminate the Universe relatively soon after the Big Bang, it looks like their existence occurred even sooner. This is what new results from the Hubble Space Telescope are pointing to.
No stars when the Universe was 500 million to 1 billion years old
And no stars obviously mean no galaxies. This is the result the team of European researchers led by Rachana Bhatawdekar from ESA (European Space Agency) came to. Bhatawdekar and her team analyzed the early Universe when it was ‘only’ 500 million to 1 billion years old. They had been studying the cluster MACSJ0416 and its parallel field using the Hubble Space Telescope. But supporting data from Very Large Telescope of the European Southern Observatory and NASA’s Spitzer Space Telescope were also involved. The leader of the team said it loud and clear:
We found no evidence of these first-generation Population III stars in this cosmic time interval
Bhatawdekar and her team created a new technique that removes the light from some of the galaxies that constitute the gravitational lenses. Thus they discovered galaxies with lower masses than they previously observed with Hubble.
Bhatawdekar also added:
These results have profound astrophysical consequences as they show that galaxies must have formed much earlier than we thought,
This also strongly supports the idea that low-mass/faint galaxies in the early Universe are responsible for reionisation.
The conclusion is that the first galaxies and stars were born in the Universe a lot earlier than scientists initially thought.