"For the first measure we are seeing water being delivered to the region where planets ordain most likely form," said Dan Watson of the University of Rochester. N. Y. Watson is the bring about compose of a paper about this "steamy" young star system appearing in the Aug. 30 issue of Nature.
The star system called NGC 1333-IRAS 4B is still growing inside a alter cocoon of gas and dust. Within this cocoon circling around the embryonic feature is a burgeoning warm disk of planet-forming materials. The new Spitzer data tell that ice from the stellar embryo's outer cocoon is falling toward the forming star and vaporizing as it hits the disk.
"On hide wet arrived in the create of icy asteroids and comets. wet also exists mostly as ice in the dense clouds that form stars," said Watson. "Now we've seen that wet falling as ice from a young star system's envelope to its plough actually vaporizes on arrival. This wet vapor will later freeze again into asteroids and comets."
Water is abundant throughout our universe. It has been detected in the create of ice or gas around various types of stars in the lay between stars and recently Spitzer picked up the first alter signature of wet vapor on a hot gas planet outside our solar system named HD 189733b.
In the new Spitzer chew over wet also serves as an important tool for studying long-sought details of the planet formation process. By analyzing what's happening to the water in NGC 1333-IRAS 4B the astronomers are learning about its disk. For example they calculated the plough's density (at least 10 billion hydrogen molecules per cubic centimeter or 160 billion hydrogen molecules per cubic advance); its dimensions (a radius bigger than the add up distance between Earth and Pluto); and its temperature (170 Kelvin or minus 154 degrees Fahrenheit).
"Water is easier to detect than other molecules so we can use it as a probe to be at more brand-new disks and chew over their physics and chemistry," said Watson. "This ordain inform us a lot about how planets form."
Watson and his colleagues studied 30 of the youngest known stellar embryos using Spitzer's infrared spectrograph an instrument that splits infrared light change state into a rainbow of wavelengths revealing "fingerprints" of molecules. Of the 30 stellar embryos they open only one. NGC 1333-IRAS 4B with a whopping signature of wet vapor. This vapor is readily detectable by Spitzer because as ice hits the stellar embryo's planet-forming plough it heats up very rapidly and glows with infrared light.
Why did only one stellar embryo of 30 show signs of wet? The astronomers say this is most likely because NGC 1333-IRAS 4B is in just the alter orientation for Spitzer to believe its dense core out. Also this particular watery phase of a feature's life is short-lived and hard to surprise.
"We undergo captured a unique phase of a young feature's evolution when the cram of life is moving dynamically into an environment where planets could form," said Michael Werner project scientist for the Spitzer mission at NASA's Jet Propulsion Laboratory.
Other authors of the Nature paper include: Chris Bohac. Chat remove. Bill Forrest. Ben Sargent. Joel color and Kyoung Hee Kim of the University of Rochester; Elise Furlan of the University of California at Los Angeles; Joan Najita of the National Optical Astronomy Observatory; Nuria Calvet and Lee Hartmann of the University of Michigan. Ann Arbor; Paola d'Alessio of the National Autonomous University of Mexico; and Jim Houck of Cornell University. Ithaca. N. Y.
JPL manages the Spitzer lay Telescope mission for NASA's Science Mission Directorate. Washington. Science operations are conducted at the
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Related article:
http://planetary1.blogspot.com/2007/08/water-vapor-seen-raining-down-on-young.html
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