An article published in the journal “Monthly Notices of the Royal Astronomical Society” describes the discovery of what appears to the largest structure of the universe. It’s a ring of nine gamma-ray bursts, which means as many galaxies, for a length of 5 billions light years. This ring, though it’s not really a circle, seems to contradict the current models and in particular the cosmological principle, the idea that the distribution of matter in the universe is uniform at a large enough scale.
When astronomers started studying a map of the cosmic microwave background radiation (CMB or CMBR), the residue of the earliest stages of the universe, they found what was called the Cold Spot. That’s a huge area colder than expected which could be the largest single cosmic structure never identified. According to an international team of scientists consists of a cosmic supervoid which about 1.8 billion light years across.
A research conducted by a team led by astronomer Peter A. Milne of the University of Arizona published in two articles in the “Astrophysical Journal” shows that Type Ia supernovae can be divided into two groups with different characteristics. For years, astronomers had thought that their brightness depended almost exclusively on their distance. This can have consequences on our knowledge of the universe expansion, also calculated based on this type of supernovae.
Nearly two years after presenting the best map ever made of the cosmic microwave background radiation, ESA revealed another map created using data collected by the Planck Surveyor space probe between 2009 and 2013. This new map shows the polarization of the cosmic microwave background radiation dating back to the early stages of the universe. It shows that the first stars started forming about 550 million years after the Big Bang, 100 million years later than previously thought.
In March 2014, the announcement that the BICEP2 (Background Imaging of Cosmic Extragalactic Polarization) experiment had detected gravitational waves in the perturbations in the cosmic microwave background radiation existing in the universe was sensational. This echo of cosmic inflation occurred shortly after the Big Bang was an extraordinary discovery. Unfortunately, a collaboration between the BICEP2 experiment and the team of ESA’s Planck space telescope has determined that those weren’t gravitational waves but probably emissions caused by galactic dust.