Italian astronomers have discovered water vapor in a disk surrounding a young star, where planets are forming. The findings, published in the journal Nature Astronomy on March 1st, reveal that within the inner disk of HL Tauri, a young star in the Taurus constellation located 450 light-years away from Earth, the water content is at least three times that of all Earth's oceans combined. This marks the first time scientists have calculated the mass of water vapor around a star.
Water is a crucial component for life on Earth and is believed to play a significant role in planetary formation. However, astronomers previously struggled to map out the distribution of water in stable stellar disks.
In this breakthrough, researchers not only captured detailed images but also analyzed water vapor at a distance of 450 light-years from Earth.
Observing water with ground-based telescopes is challenging due to the abundant water vapor in Earth's atmosphere, which interferes with astronomical signals. This new discovery owes its success to the Atacama Large Millimeter/submillimeter Array (ALMA), capable of resolving details as small as a human hair within a range of one kilometer. Situated at an altitude of approximately 5000 meters, ALMA operates in a high and dry environment, providing ideal observation conditions. So far, ALMA remains the only facility capable of mapping out the distribution of water in distant planet-forming disks.
Researchers found a significant amount of water in the disk around HL Tauri, where celestial bodies are avidly gathering material for planet formation. Water vapor may influence the chemical composition of planets in this region.
They explain that the dust particles comprising the disk are the "seeds" for planet formation, colliding and aggregating into larger bodies orbiting the star. In regions with sufficiently low temperatures, water can freeze onto dust particles, facilitating more efficient material aggregation, making it an ideal site for planet formation.
