Web Telescope discovers strange planet-forming disks around infant stars!

"This challenges the current models of disk chemistry and evolution."

August 29, Space News reported.

This is an illustration of a protoplanetary disk surrounding an infant star. Figure 1

Using the James Webb Space Telescope (JWST), astronomers discovered a strange gas and dust disk around an infant star,

which may challenge current planetary formation models.

The chemical composition of this protoplanetary disk is unusual.

It has unexpectedly high levels of carbon dioxide in the region where terrestrial planets like Earth are expected to form, and surprisingly low water content.

"In fact, the water in this system is extremely scarce, almost undetectable.

This is in sharp contrast to what we usually observe."

Strange chemical reactions.

Stars form from massive clouds of gas and dust, when dense regions come together, eventually accumulating enough mass for gravitational collapse.

Scientists currently theorize that planetary formation occurs when pebbles rich in water ice drift from the colder outer regions of the protoplanetary disk to its warmer inner regions.

Higher temperatures cause solid ice to directly convert into gas, a process known as sublimation.

This usually also leads telescopes such as JWST to detect strong water vapor signals in protoplanetary disks.

However, the disk around XUE 10 shows strong carbon dioxide signals.

"The discovery of such a high abundance of carbon dioxide in the region of planetary formation is unexpected.

This suggests that strong ultraviolet radiation—either from the host star or neighboring stars—is reshaping the disk's chemical composition."

This is not the only surprise that JWST has brought to the team regarding XUE 10 and its protoplanetary disk.

Data from the disk revealed carbon dioxide molecules enriched with carbon isotopes carbon-13 and oxygen isotopes oxygen-17 and oxygen-18.

The presence of these isotopes may help explain why certain unusual isotopic meteorites and comets formed in the debris of the early solar system.

This study demonstrates that JWST can impressively detect chemical features in distant protoplanetary disks during the critical period of planetary formation.

The team's research was published in the journal Astronomy & Astrophysics on Friday (August 29).

Original: www.toutiao.com/article/1841831939956748/

Statement: This article represents the views of the author.