Jun 30 2005
From The Space Library
An international group of astronomers led by Debra A. Fischer of San Francisco State University announced that they had discovered the largest solid core yet found in an exoplanet. The planet, called HD 149026b, has a solid core that is approximately 70 times larger than Earth's mass. The discovery was the first observational evidence of the core accretion theory of planetary formation, which posits that planets begin as small rock-ice cores and acquire additional mass through gravitational attraction of gas and other matter. The competing gravitational instability theory holds that planetary formation occurs after the rapid gravitational collapse of large gas clouds. Fischer and the other astronomers reported that they had determined that the mechanism of gravitational instability was unlikely to have produced the large, rocky core of HD 149026b. (NASA, “NASA Researchers Discover Planet with Largest Solid Core,” news release 05-169, 30 June 2005; Bun'ei Sato et al., “The N2K Consortium. II. A Transiting Hot Saturn Around HD 149026 with a Large Dense Core,” Astrophysical Journal 633, no. 1 (1 November 2005): 465-473.)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
