Saturday, March 12, 2005
The Skinny on Fat Stars
Astronomers using the Hubble Space Telescope say they've measured how fat a star can get. Studying the densest known star cluster in the Milky Way galaxy, the Arches cluster, they determined that stars can't get any larger than about 150 times the mass of our Sun, or 150 solar masses. That's a barely bare bones image of the burning behemoths they expected to find
"Standard theories predict 20 to 30 stars in the Arches cluster with masses between 130 and 1,000 solar masses, but we found none" said Donald F. Figer of the Space Telescope Science Institute in Baltimore, Md. "If they had formed, we would have seen them."
The discovery that stars have a weight limit offers an important to clue to how stars form, burn and die. "Even with the advances in technology, astronomers do not know enough about the details of the star-formation process to determine an upper-mass limit for stars," said Figer.
Astronomers have been debating for at least a century how large a star can get before it blows itself apart. Stars are cosmic foundries forging hydrogen into heavier atoms like carbon, oxygen, iron and all the rest of the elements that make people, dogs, trees and the rest the the visible universe. The elements scatter through space when stars go supernova in a cataclysmic explosion.
Figer spent seven years studying the Archer cluster. His paper appears in the current issue of Nature.
"Standard theories predict 20 to 30 stars in the Arches cluster with masses between 130 and 1,000 solar masses, but we found none" said Donald F. Figer of the Space Telescope Science Institute in Baltimore, Md. "If they had formed, we would have seen them."
The discovery that stars have a weight limit offers an important to clue to how stars form, burn and die. "Even with the advances in technology, astronomers do not know enough about the details of the star-formation process to determine an upper-mass limit for stars," said Figer.
Astronomers have been debating for at least a century how large a star can get before it blows itself apart. Stars are cosmic foundries forging hydrogen into heavier atoms like carbon, oxygen, iron and all the rest of the elements that make people, dogs, trees and the rest the the visible universe. The elements scatter through space when stars go supernova in a cataclysmic explosion.
Figer spent seven years studying the Archer cluster. His paper appears in the current issue of Nature.
