It has been operating for over 30 years and despite the growing hardware problems it continues to give priceless results; we are talking about the Hubble Space Telescope, which just recently set a new record by identifying what it is today the most remote but seen star.
An incredible result that surpasses the previous record (also by Hubble) and not a little, in fact, if the 4 billion light-years away from the Earth of the star Icarus seemed something unsurpassable, the light of the star recently detected it took 12.9 billion light years to reach our planet. We could therefore be faced with one of the first generations of stars born after the Big Bang in the early expansion stages of the universe, which scientists estimate to be around 13.7 billion years old. We had previously observed celestial bodies at similar distances, but they were star clusters and not single stars, as in this case. The document describing the discovery was published on Nature on March 30 and thanks to it we discover that the star has been called Earendel, which in Old English means “morning star”.
Brian Welch himself, an astronomer at Johns Hopkins University in Baltimore and lead author of the paper, said he was appalled by the discovery. “Normally at these distances, entire galaxies look like tiny spots, with the light of millions of stars merging together.”said the scientist.
Once again Albert Einstein’s hypotheses are confirmed, since Earendel’s identification was accomplished thanks to an effect predicted by the theory of general relativity and called “gravitational lens”. Normally a star like Earendel positioned at this distance would be impossible to spot, but luckily a huge cluster of galaxies called WHL0137-08 came in handy and positioned in line of sight between the Earth and the star.
If theoretically a celestial body should not be visible, the gravitational attraction of the cluster of galaxies is so intense that it deforms the fabric of space and time and bends light in a similar way to that operated by a lens, while operating at the same time. a powerful magnifying effect on objects placed behind. The distortion of the light coming from the galaxy that hosts Earendel has the appearance of a crescent and is clearly visible in the image posted above. The researchers also gave it a name, it’s called the Sunset Arc.
Earendel is estimated to have a mass 50 times greater than that of the sun and be millions of times brighter, nevertheless it would still be invisible without the effect of gravitational lens. It is thought to be one of the primary stars in the formation of the universe, and as such it could only be formed of hydrogen and helium, but the research team wants to know more and luckily the new James Webb space telescope will soon be able to come to our aid.
The powerful medium, currently in the final alignment phase of the mirrors, will be able to provide us with further details on Earendel’s composition, measure its temperature and brightness. These characteristics could revolutionize everything we know about the birth of the universe and the processes immediately following it, remember that Earendel could have formed only 800 million years after the Big Bang. It is good to remember that what we see today may no longer exist and indeed, given the mass of the star it is very likely that its life cycle has been exhausted within a few million years and that what we see is only a snapshot. of the celestial body as it was 12.9 billion years ago. Fascinating, isn’t it? We will continue to follow the developments of this study.