Dusty Shock Waves Create Raw Materials for Planets
A team of astronomers led by Professor William Forrest and graduate student Ben Sargent have discovered that "[s]hock waves around dusty, young stars might be creating the raw materials for planets," according to a recent NASA press release. Using NASA's Spitzer Space Telescope, the researchers found the first evidence of cristobalite and tridymite crystals around several stars just beginning to transition into planets. These particular crystals require "flash heating events, such as shock waves, to form."
A type of silica, the crystals develop only under temperatures of approximately 1,220 Kelvin (1,740 degrees Fahrenheit). The disks that eventually become planets are too cold to enable creation of the cristobalite and tridymite crystals. The disk temperatures range from 100 to 1,000 Kelvin (minus 280 to positive 1,340 degrees Fahrenheit). Hence, Forrest and his team concluded that heating followed by rapid cooling -- perhaps shock waves -- might be responsible for creating the newly found crystals.
The research findings will appear in the Astrophysical Journal, and along with Forrest and Sargent, the other co-authors include: C. Tayrien, M.K. McClure, A.R. Basu, P. Manoj, Dan Watson, C.J. Bohac, K.H. Kim and J.D. Green of the University of Rochester; A Li of the University of Missouri, Columbia; E. Furlan of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and G.C. Sloan of Cornell University, Ithaca, N.Y.
[photo and caption, above left, from NASA/JPL-Caltech: NASA's Spitzer Space Telescope has, for the first time, detected tiny quartz-like crystals sprinkled in young planetary systems. The crystals, which are types of silica minerals called cristobalite and tridymite, can be seen close-up in the black-and-white insets (cristobalite is on the left, and tridymite on the right). The main picture is an artist's concept of a young star and its swirling disk of planet-forming materials.]
(photo, above right, University of Rochester: Professor William Forrest)