sheeny
09-06-2006, 08:16 AM
The Following is the first paragraph from a letter in physics@nature this morning:
Stabilization of the disk around http://www.nature.com/__chars/beta/black/bold/big/glyph.gif Pictoris by extremely carbon-rich gas
Aki Roberge1 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a1), Paul D. Feldman2 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a2), Alycia J. Weinberger3 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a3), Magali Deleuil4 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a4) and Jean-Claude Bouret4 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a4)
Top of page (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#top) The edge-on disk surrounding the nearby young star http://www.nature.com/__chars/beta/black/med/base/glyph.gif Pictoris is the archetype of 'debris disks', which are composed of dust and gas produced by collisions between—and evaporation of—planetesimals, analogues of Solar System comets and asteroids. These disks may provide insight into the formation and early evolution of terrestrial planets. Previous work on http://www.nature.com/__chars/beta/black/med/base/glyph.gif Pic concluded that the disk gas has roughly solar abundances of elements1, but this poses a problem because such gas should rapidly be blown away from the star, contrary to observations showing a stable gas disk in keplerian rotation1, 2. Here we report the detection of singly and doubly ionized carbon (C ii, C iii) and neutral atomic oxygen (O i) gas in the http://www.nature.com/__chars/beta/black/med/base/glyph.gif Pic disk. Carbon is extremely overabundant relative to every other measured element. This appears to solve the problem of the stable gas disk, because the carbon overabundance should keep the gas disk in keplerian rotation3. The overabundance may indicate that the gas is produced from material more carbon-rich than expected of Solar System analogues.
Enjoy,
Al.
Stabilization of the disk around http://www.nature.com/__chars/beta/black/bold/big/glyph.gif Pictoris by extremely carbon-rich gas
Aki Roberge1 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a1), Paul D. Feldman2 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a2), Alycia J. Weinberger3 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a3), Magali Deleuil4 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a4) and Jean-Claude Bouret4 (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#a4)
Top of page (http://www.nature.com/nature/journal/v441/n7094/abs/nature04832.html#top) The edge-on disk surrounding the nearby young star http://www.nature.com/__chars/beta/black/med/base/glyph.gif Pictoris is the archetype of 'debris disks', which are composed of dust and gas produced by collisions between—and evaporation of—planetesimals, analogues of Solar System comets and asteroids. These disks may provide insight into the formation and early evolution of terrestrial planets. Previous work on http://www.nature.com/__chars/beta/black/med/base/glyph.gif Pic concluded that the disk gas has roughly solar abundances of elements1, but this poses a problem because such gas should rapidly be blown away from the star, contrary to observations showing a stable gas disk in keplerian rotation1, 2. Here we report the detection of singly and doubly ionized carbon (C ii, C iii) and neutral atomic oxygen (O i) gas in the http://www.nature.com/__chars/beta/black/med/base/glyph.gif Pic disk. Carbon is extremely overabundant relative to every other measured element. This appears to solve the problem of the stable gas disk, because the carbon overabundance should keep the gas disk in keplerian rotation3. The overabundance may indicate that the gas is produced from material more carbon-rich than expected of Solar System analogues.
Enjoy,
Al.