New analyzes of the cosmic disk of dust and gas surrounding a small star have revealed that there is a large amount of water vapor in a specific area where small planets begin to form.
Astronomers have, for the first time, mapped the distribution of water in a “planet-forming disk” around a star that could be hospitable to life.
HL Tauri, a Sun-like star located just 450 light-years from the Solar System, could help us understand the origin of water on Earth.
Astronomer Stefano Facchini from the University of Milan says: “Our latest images reveal a large amount of water vapor far from the star, including the space where a planet is now likely to form. Image of steam oceans.” “Water is in the same region where a planet could form.”
Stars are born in dense clouds of dust and gas, where a very dense knot collapses under the influence of gravity and begins to rotate, organizing the material around the growing central star into a disk that surrounds the growing star.
Once a star forms, any matter not affected by gravity and not pulled by the star begins to merge with its surroundings to form other matter in the planetary system: planets, moons, asteroids, and comets.
Observations by the Atacama Large Millimeter/Submillimeter Array (ALMA) reveal concentric gaps in the disc surrounding HL Tauri. Astronomers believe they are the result of the formation of planets and the filtering of material from the disk as it orbits the star.
The research team used ALMA to take new observations of the star, using two different wavelength bands to target water vapor. They found large amounts of water in the inner part of the disk, within 17 AU of the star, where Earth-like planets are expected to form. This area contains 3.7 times more water than all the Earth's oceans.
The researchers found water in known, prominent gaps in the disk, meaning any planet that forms there has a good chance of being incorporated into water.
“Our results show how the presence of water can affect the evolution of a planetary system, as it did in our solar system about 4.5 billion years ago,” says Facchini.
