The strange planet-forming disc is full of carbon dioxide in areas where planets can form like Earth, with fresh observations from James Webb’s Space Telescope (JWST) show.
Although the disks that form such planets usually contain water, “there is very little water in this system, and this is a dramatic contrast to what we normally observe,” said Jenny Frediani, a doctoral student at Stockholm University and a lead author of the study, in a statement.
The findings published on August 29 in Journal Astronomy & Astrophysics challenge current ideas about planetary layers.
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The science team still doesn’t know what’s going on with the NGC 6357 star, located 8,000 light years from Earth, Frediani told Live Science in an email. However, further investigation of this system could help us understand more about the formation of planets like Earth.
“These are the most common environments for the formation of stars and planets, and are likely similar to the environment in which our own solar system was formed,” Frediani told Live Science.
Strange Star
Usually, newborn stars are enveloped in gas clouds. They create discs of materials where planets and other objects, such as comets and asteroids, may eventually form.
Previous models suggest that as these discs evolve, small pieces of rocky material rich in water ice migrate from the outside of the planetary-forming disc and from the cold edge to the warm center. As the pebble moves towards the younger star, the temperature on the rock surface increases, sublimating the ice. JWST can find this sublimation through a steam signature.
However, when JWST looked into this star known as the Xue 10, it discovered a surprise: the carbon dioxide signature.
There are two theories that can explain strange environments, Frediani explained.
One possibility is a powerful source of ultraviolet (UV) radiation from a newborn or nearby stars. “Boths emit sufficient UV rays and can significantly deplete the reservoirs in the disc early on,” she said.
Another reason may be due to dust grains in the area. Rather than coating a large amount of grain, she said, it was filled with dust with carbon dioxide, perhaps due to certain local environmental conditions around the young star.
If this is the case, water vapor will stick to the stars, but “relatively large amounts of CO2″ [carbon dioxide] The steam remains visible on the disc before it finally adheres to it,” explained Frediani.
JWST is located in a gravity-stable space known as the Lagrange Point, far from interfering with light from the Earth and other celestial bodies. Its remote location, combined with the powerful mirror of JWST, becomes the only sensitive enough to capture details about how planetary disks form in remote and large star-forming regions, Frediani said.
Frediani is part of an extreme UV environmental collaboration, examining how intense radiation fields affect the chemistry of the discs around the planet-forming stars. For now, JWST continues to be the consortium’s best bet for following up on this strange system, but some ground observatory and upgrades will help, Frediani said.
For example, a long-term European Southern Observatory-led large millimeter/sub-millimeter array in the Atacama Chilean Desert has been upgraded in the hopes of operating the changes by the 2030s.
The wideband sensitivity upgrade, as called work, “can imagine a reservoir of cold gas and dust in the area outside the disc in the distant star-forming region,” Frediani said. This upgrade should allow researchers to see the root cause of phenomena such as disk truncation (or shrinking) that occurs due to strong external illumination.
Another complementary ground observatory is the extremely large telescope (ELT), a 130-foot (39-meter) ESO observatory under construction in Chile. According to ESO, when completed around 2027, the ELT will be the largest of the next generation of ground-based optics and near-infrared telescopes.
“ELT is strong enough to resolve the fine structures of these irradiated discs, revealing substructures that can be linked to, for example, the formation of planets within the disc,” Frediani said.
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