Water molecules are key components in the formation of planetary systems. Astronomers using the Atacama Large Millimeter/Submillimeter Array (ALMA) have detected water vapor in the disk around the young star HL Taurus, where planets may be forming. Their analysis suggests that the hard lower limit for water vapor availability within the interior 17 astronomical units of the Taurus HL system is 3.7 Earth Oceans.
This ALMA image shows water vapor (blue tints) in the protoplanetary disk around HL Taurus. Near the center of the disk, where young stars live, the environment is hotter and the gas brighter. The red ring is a previous ALMA observation showing the distribution of dust around the star.Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Facchini other.
Water molecules are undoubtedly one of the most important molecular species in the entire universe.
Water is a highly efficient solvent, so it played a key role in the emergence of life as we know it on Earth.
For this reason, chemical characterization of exoplanetary atmospheres often focuses on detecting this specific molecule.
Water, formed from common hydrogen and oxygen atoms, is so abundant in both gas and ice form that it plays a fundamental role in the physics of planetary system formation.
Dr Stefano Facchini, an astronomer at the University of Milan, said: “We never imagined that we would be able to image oceans of water vapor in areas where planets are likely to form.”
The HL Taurus system is believed to be less than 100,000 years old and has a radius of about 17.9 billion km. It is located 450 light years away in the direction of the constellation Taurus.
The protoplanetary disk of HL Taurus is unusually large and bright, making it a perfect place to look for signs of planet formation.
New ALMA observations reveal that there is at least three times more water inside the disk than in Earth's entire ocean.
Dr Leonardo Testi, an astronomer at the University of Bologna, said: “It is truly amazing that we can not only detect water vapor 450 light-years from us, but also obtain detailed images and spatially resolve it.” said.
Spatially resolved observations with ALMA allow astronomers to determine the distribution of water in different regions of the disk.
“Participating in such an important discovery of the iconic HL Taurus disk was beyond my expectations given my first research experience in astronomy,'' said Dr. Mathieu Vander Donk, an astronomer at the University of Liege. he said.
Dr Facchini said: “Our recent images reveal that significant amounts of water vapor are present at distances from the star that include gaps where planets may now be forming.” said.
“This suggests that this water vapor could influence the chemical composition of planets that form in those regions.”
“To date, ALMA is the only facility capable of spatially resolving water in cold planet-forming disks,” said Professor Wouter Bremings, an astronomer at Chalmers University of Technology.
ESO astronomer Dr Elizabeth Humphreys said: “It's really exciting to be able to witness first-hand in photographs the ejection of water molecules from icy dust particles.”
“The dust particles that make up the disk are the seeds for planet formation, colliding and clumping together to form even larger bodies orbiting the star.”
“Our findings show how the presence of water influences the development of planetary systems, similar to our own solar system about 4.5 billion years ago,” Dr. Facchini said.
of findings It was published in the magazine natural astronomy.
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S. Facchini other. HL Resolved ALMA observations of water in the inner astronomical unit of the Tau disk. Nat Astron, published online on February 29, 2024. doi: 10.1038/s41550-024-02207-w
Source: www.sci.news
