A major scientific discovery on the role of giant stars in the birth of the solar system

CNRS researchers have made a major discovery: the importance of radiation from massive stars in the formation of planetary systems. Explanations.

They have been studying the Orion Nebula for over a year and a half. CNRS astrophysicists then made a major discovery about the origin of planetary systems.

The Orion Nebula is a stellar nursery. Inside, CNRS scientists are studying the birth of a planetary system called “d203-506”.

Because planets don’t form alone but within star clusters where there are tens or thousands of them. Within these star clusters, stars as we know them but also massive stars coexist. These spread over a distance of many light years. In comparison, they are 100,000 times brighter than the Sun.

These massive stars, through their ultraviolet radiation, play a crucial role in the formation of planetary systems. Depending on the mass of the star at the center of the system, this radiation can promote the formation of planets or lead to their destruction. “They heat the material around these young stars and create flows”Olivier Bernay, researcher at CNRS and head of the Orion project, explains. “The material then escapes from the star and is no longer available to form planets. So these massive stars can suppress the formation of planetary systems.” The situation observed on the d203-506 system, of insufficient density, makes it unlikely to progress beyond the embryonic stage.

The same thing happened during the formation of the Solar System: one (or more) massive stars radiated onto the forming Sun. But this time, the Sun, due to its mass and the importance of its gravity, was able to resist the effects of this star’s radiation and continue its growth.

This giant star has now disappeared. None of them live more than a few million years. Sun is 4.5 billion years old.

The role of these big stars has been little or no study till now. The power of the James Webb Telescope makes it possible for the first time to study them and determine their action. “James Webb sent us very precise observations of the density or temperature of these massive stars”Astrophysicists suggest. “We now have information that we lacked to describe and measure the impact of these stars on emerging planetary systems.”

Information used by researchers at CNES, CNRS, Toulouse Sabatier University, Paris-Saclay University, Sergiy Paris University, Paris-PSL Observatory and Sorbonne University to lead to this study. The results, of unprecedented precision, are published on the front page of Science magazine this Friday, March 1.

These researchers now hope to once again see their program selected by NASA for operation of the James Webb Telescope. Continuing their work will make it possible to study the action of giant stars on Orion’s other planetary systems, to detect water molecules within the nebula, but also to study the behavior of wandering planets.