Washington, March 14 : Researchers using NASA's Spitzer Space Telescope have discovered large amounts of simple organic gases and water vapor in a possible planet-forming region around an infant star, along with evidence that these molecules were created there.
In their project, John Carr of the Naval Research Laboratory, Washington, and Joan Najita of the National Optical Astronomy Observatory, Tucson, Arizona, took an in-depth look at the gases in the planet-forming region in the disk around the star AA Tauri.
Less than a million years old, AA Tauri is a typical example of a young star with a protoplanetary disk.
By developing a new technique using Spitzer's infrared spectrograph, the researchers were able to measure and analyze the chemical composition of the gases within the protoplanetary disk.
It is a flattened disk of gas and dust that encircles young stars. Scientists believe they provide the building materials for planets and moons and eventually, over millions of years, evolve intorbiting planetary systems like our own.
With their new procedures, they were able to detect the minute spectral signatures for three simple organic molecules - hydrogen cyanide, acetylene and carbon dioxide - plus water vapor.
In addition, they found more of these substances in the disk than are found in the dense interstellar gas called molecular clouds from which the disk originated.
"Molecular clouds provide the raw material from which the protoplanetary disks are created," said Carr. "So this is evidence for an active organic chemistry going on within the disk, forming and enhancing these molecules."
By pushing the telescope's capabilities to a new level, astronomers now have a better view of the earliest stages of planetary formation, which may help shed light on the origins of our own solar system and the potential for life to develop in others.
Using the new information obtained from the telescope, astronomers will be able to fill an important gap - they know that water and organics are abundant in the interstellar medium but not what happens to them after they are incorporated into a disk.
"Now that we can identify these molecules and inventory them, we will have a better understanding of the origins and evolution of the basic building blocks of life - where they come from and how they evolve," said Carr.
According to Geoffrey Blake, professor of cosmochemistry and planetary sciences at Caltech, "With upcoming Spitzer observations and data in hand, we will develop a good understanding of the distribution and abundance of water and organics in planet-forming disks."