Great attractor

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Panoramic view of the sky in the near infrared - the location of the large attractor is indicated by the long blue arrow that starts at the bottom right of the screen

The Great Attractor is a supercluster and one of the most massive structures known in the universe . It has a mass in the order of magnitude of 10 quadrillion solar masses (10 16  M ☉ ) and is about 150 to 250 million light-years away from the earth (approx. 1.4–2.4 × 10 24  m). The center of gravity is in the Norma galaxy cluster - south of Scorpio  - which is difficult to observe because it is almost entirely hidden in the plane of the Milky Way when viewed from Earth .

This significant gravitational anomaly , which affects the Virgo supercluster , the Great Wall with the Coma cluster and also the Hydra-Centaurus supercluster , was discovered in 1990 (according to other sources, 1986) through irregularities in the Hubble River . This means that the galaxy clusters in this area move away from each other less quickly than would be the case with a homogeneous expansion of the universe .

Since the assumed mass of the Norma galaxy cluster and other known structures alone does not seem to be sufficient to explain the effect, other structures hidden by the Milky Way are assumed to be sources of attraction. The Shapley supercluster is assumed to be a possible cause of the gravitational pull .

In February 2016, a team of scientists from the University of Western Australia and Curtin University in Australia , led by Lister Staveley-Smith, announced on the website of the International Center for Radio Astronomy Research (ICRAR) that there were 883 galaxies previously hidden behind the Milky Way in the realm of the larger Having registered attractors, a third of which were previously unknown galaxies. The 250 million light years from Earth distant galaxies with a radio telescope of the Parkes Observatory of CSIRO discovered was therefore equipped with a special receiver. However, this discovery did not provide the hoped-for explanation for the lack of mass in the large attractor.

literature

Source references

  1. ↑ Behind the Milky Way: Hundreds of galaxies discovered in the Great Attractor
  2. ^ ICRAR: Scientists discover hidden galaxies behind the Milky Way
  3. ^ Lister Staveley-Smith: Explainer: what is the Great Attractor and its pull on our galaxy? . The Conversation / universal-sci.com, May 31, 2016.

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