The Hubble Space Telescope discovers the oldest and most distant star: Erendel

An international team of astronomers led by Brian Welch From Johns Hopkins University (USA) and with the participation of researchers from CSIC and the University of the Basque Country, Erendel, The most distant star ever recorded. The report is published in the journal Ბունება.

“Earendel existed in the first billion years of the universe, during the Big Bang, and its light traveled. 12.9 billion years “Before reaching the earth,” explains one of the authors, Jose Maria DiegoResearcher at the Cantabria Institute of Physics (IFCA, CSIC-UC).

The star no longer exists, it exploded millions of years ago, but its light was so strong that it is still visible and discovered by the Hubble Space Telescope. It shone when the universe was young, just a billion years after the Big Bang (which occurred 13.8 billion years ago), and was much more massive and bright than the sun.

The discovery of Earendel, located 12.9 billion light-years from us, far exceeds the most distant star ever recorded: Icarus, located 9 billion light-years from Hubble.

Earendel’s discovery far exceeds the discovery of the farthest star ever recorded: Icarus, Discovered in 2018 by the Hubble Space Telescope at a distance of 9000 million light years. It also opens a window to learn about the early days of the universe and the origin of the first star.

“His discovery represents a bigger leap in time than the previous Icarus record; “It allows us to go back much further to the origin of the universe,” Diego notes. It exploded a long time ago, but we can still see the light coming from it. We were able to discover it thanks to the fact that it is magnified by a cluster of galaxies; If not, it would be impossible. ”

The star got its name from the poem Erendel’s JourneyThe Evening Star, written in 1914 by John Ronald Reuel Tolkien, author Lord of the RingsWhich was inspired by Anglo-Saxon mythology.

Magnified magnified star by gravitational lensing

As the universe expands, light from distant objects stretches or shifts to a larger wavelength as they approach Earth. Until now, such long-distance objects have been responding to clusters of stars embedded in the first galaxies.

We were able to discover it thanks to the fact that it is magnified by a cluster of galaxies; If not, it would be impossible

Jose Maria Diego
– (IFCA, CSIC-UC)

“Normally, galaxies at these distances are perceived as tiny spots because the light of millions of stars is mixed,” says Diego. The host of the galaxy Eärendel “It was magnified and distorted by gravitational lensing.”

“Just as curved glass distorts an image when we look at it, a gravitational lens amplifies the light of very distant objects aligned behind a cluster of galaxies. “These galaxies are the ones that emit distant stars because their enormous mass deforms the space-time around them,” explains the researcher.

The group estimates that Earendel will be at least 50 times the mass of the Sun and will be much brighter than the Sun, thus competing with the most famous massive stars.

“Is Primary stars (Which are formed from elements formed soon after the Big Bang: traces of hydrogen, helium and lithium) have not yet been detected by observers, but can now be detected if we look at high-power gravitational lenses as they did. Earendeli “, comments Welch.

The group estimates that Earendel will be at least 50 times the mass of the Sun and will be much brighter than the Sun, thus competing with the most famous massive stars.

“They are the first generation and we knew almost nothing about them. From now on, with similar stars, we will be able to study them in detail with similar telescopes James Webb. In fact, there is already a monitoring program approved by NASA and in which we participate, “he added.

“Erendel’s study will be a window into an era of the universe that we do not know, but that led to everything we know. It’s like we’re reading an interesting book, but we start with the second chapter and now we have the opportunity to see how it all started, “Welch concluded.

For his part, researcher at the Andalusian Institute of Astrophysics (IAA-CSIC) and co-author Yolanda Jimenez Tea Explains that “in order to predict whether Erendel will remain bright for years, if it is temporary, we must estimate the mass of all the stars in the line of sight between us and Erendel.”

Expected Contribution of James Webb

Since the data indicate that the star will continue to shine for years, the next step will be to study it with the James Webb Space Telescope. Astronomers hope that in 2022 Erendel will be able to see himself expanding with this observatory, which opened in late 2021 and is led by the American, European and Canadian space agencies (NASA / ESA / CSA).

With the Web Telescope it will be possible to learn more about the composition of this star, which is a topic of particular interest to astronomers as it formed before the universe was filled with heavy elements.

“Web images and spectra will allow us to prove that Erendel is actually a star and reduce its age, temperature, mass and radius,” explains Diego. Welch adds, “Combining Hubble and Webb observations will allow us to understand microlensing in a cluster of galaxies that may contain exotic objects such as Primary black holes“.

In addition, the telescope will be able to learn more about the composition of this star, which is of particular interest to astronomers as it formed before the universe was filled with heavy elements generated by several generations of massive stars.

“We are going to study a lot: we will get the spectrum, or the star’s fingerprint, it will tell us how old it is, how long it was born, how long it was alive when we see the light. “It was radiant now, whether it was metal or its constituent elements,” Diego concludes.