Astronomers Detect Heavy Water in Planet-Forming Disk Around Young Star

For the first time, researchers have detected the presence of heavy water in a disk where planets are forming around a young star known as V883 Orionis, located about 1,350 light-years away. Using the Atacama Large Millimeter/submillimeter Array (ALMA), scientists observed that this water, despite being created in the oxygen family of chemical reactions, survives labor and delivery — emanating from a newborn star long before it becomes part of planets or comets. The finding suggests that part of the water now found in developing planetary systems may have originated beyond light-years and survived the turbulent process of becoming a star.

Ancient Heavy Water Discovery Links Interstellar Clouds to Planetary Formation

As per a Nature Astronomy report, astronomers detected deuterium, a heavier isotope of hydrogen, in the disk, creating heavy water. "It was not clear before that the water found in planets and comets had a special origin," said John Tobin of the National Radio Astronomy Observatory. "Whether it came from star-forming regions like our own solar system, or whether it formed even earlier in the history of the universe and was incorporated into interstellar ices that make up part of a planet or comet.

The ALMA data provided a crucial piece of evidence with the detection of a high level of heavy water in comparison to ordinary water, which is indicative of unprocessed molecular gas that forms before stars are born.

Margot Leemker of the University of Milan, who led the research, said that this detection shows that the water is older than and not a remnant from the star.

Researchers believe that comets forming in V883 Orionis's disk would carry the same ancient water signature. As Tobin pointed out, the detection provides “a missing link between clouds, disks, comets, and planets”, revealing how water travels across cosmic time to reach worlds like ours.