See the largest number of individual stars in the Dragon Arc galaxy

2025/01/15 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Astrofisika

An international team of astronomers has photographed over 40 individual stars in a distant universe. In fact, its light, to reach Earth, has taken half the age of the universe, that is, almost 6.5 billion light years. Ikerbasque researcher Tom Broadhurst (UPV/EHU), who works at the DIPC and at the UPV/EHU, has been one of the team members and the results have been published in the journal Nature Astronomy.

The observation has been carried out with the NASA James Webb Space Telescope (JWST), and thanks to its great sensitivity they have identified a total of 44 stars. According to researchers, this is an unprecedented achievement, as so many stars have never been identified individually.

Astrophysicists have discovered the stars in the observation of photographs taken by the JWST on a galaxy known as the Dragon Arc, after a mass cluster of galaxies called Abell 370. In fact, gravitation produces what is known as the effect of the gravitational lens: the backlight (Dragon's Bow) deforms, and instead of the conventional spiral (which is what would look without this effect), you see a corridor with cosmic proportions.

The group has analyzed the colors of each star within the Dragon Arc and found that many of these stars are red supergiants, similar to those of Betelgeus, in the constellation of Orio, in the late times of his life. In the previous discoveries, they identified mostly blue supergiants like Rigel and Deneb, one of the brightest stars in the night sky. According to the researchers, in this difference between the types of stars, JWST's ability in infrared wavelengths stands out.

In the following observations they hope to find more magnified stars in the Dragon Arc galaxy and receive answers to some questions about dark matter. In particular, the UPV/EHU team, involving Tom Broadhurst, George Smoot, Nobel Prize in Physics and Morillo Paloma, has explained in a recent article that the positions of stars in the Dragon Arc show that dark matter is similar to waves and not to heavy particles.