Astronomy | Two years of discoveries by James Webb

The space telescope James Webb has been stationed beyond the Moon for two years now. His images caused surprises among astrophysicists. Here are five of his most notable discoveries.

Protoplanetary disks


The protoplanetary disk observed around the star d203-506

In the Orion Nebula, 1350 light years from Earth, James Webb detected a “protoplanetary disk” around a young star called d203-506. This protoplanetary disk is composed of dust which will eventually form planets. Last June in Nature, an international team announced that a molecule essential to life, methylium, has been measured in the protoplanetary disk of d203-506. Methylium promotes the growth of molecules composed of carbon.

Binary objects

They were called JuMBOs, “Jupiter-mass binary objects.” Also in the Orion Nebula, these JuMBOs are too small to be stars, but also do not appear to be orbiting stars. More than forty JuMBOs have been identified by researchers from the European Space Agency, who announced their discovery last October on a scientific pre-publication site. They suggest that JuMBOs could have been born in regions of the nebula where there is not enough material to form a star.

Hidden stars


The Pillars of Creation as seen through the telescope James Webb

It is difficult to see the birth of stars in the clumps of dust and gas where they form. In the M16 cluster in the Serpent constellation, 6500 light years away, James Webb revealed dozens of very young stars, as well as the jets of material they eject in their first million years of existence. This region of space, sometimes nicknamed “Pillars of Creation” because of its spectacular appearance, was revealed by Hubble which, however, could not see the emerging stars.

Impossible galaxies


The galaxy in the center of the white square in this photo taken by James Webb was present 350 million years after the Big Bang.

The telescope James Webb was also able to see very old galaxies, which formed less than half a billion years after the Big Bang. The catch is that these galaxies are brighter than they should be according to current models of star formation. A seminar on these “impossible galaxies” bringing together around sixty astrophysicists from around the world is taking place this week at the Sesto Astrophysics Center, in northern Italy.

The first black holes


A supermassive black hole has been detected in the galaxy GN-z11, present only 400 million years after the Big Bang.

Equally “impossible” black holes have been detected by James Webb. In mid-January in Nature, for example, an international team of astrophysicists described a black hole that appeared 400 million years after the Big Bang, but reached a mass 1.6 million times greater than our Sun. This means a growth rate of this black hole five times faster than current theories.


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