A team of NASA astronomers, using the Hubble Space Telescope, has discovered that the universe is expanding much faster than previously thought. To reach this conclusion, scientists have measured the distance between the stars in various galaxies – with unprecedented precision – finding that the universe is expanding between 5 and 9% faster than the calculation derived from the measurements made. shortly after the Big Bang , with a newborn universe.
Possible explanations
Why is the universe expanding so rapidly? According to astronomers, the reason would be a new type of subatomic particle called “dark radiation” that could have changed the energy balance of the early cosmos.
“This surprising finding may be an important clue to understanding those mysterious parts of the Universe that make up 95% of everything and do not emit light , such as dark energy, dark matter, and dark radiation,” explains Nobel Prize winner Adam. Riess, research leader.
According to the calculations of Riess and his team, the margin of error is barely 2.4%, thanks to the refinement of the measurements using new techniques capable of increasing the precision with which the distances at which galaxies are found are measured. further afield.
Thus, 2,400 Cepheids (stars between 4 and 20 times the mass of the sun with very regular periods) were measured in 19 different galaxies that also contained type 1A supernovae and subsequently compared the brightness observed in both types of stars. The result was a highly accurate estimate of the distance at which nearly 300 type 1A supernovae were found in remote galaxies.
By equating these measurements with the rate of expansion of space, astronomers were finally able to calculate a new value at the Hubble constant, in light of how fast the universe is expanding in time.
The study will be published soon in The Astrophysical Journal.
