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View Full Version : The Case of the Stolen Stars



Fraser
2006-Feb-08, 06:02 PM
SUMMARY: At some point in the distant past, our own Milky Way robbed the low-mass stars from globular cluster M12. This cluster is about 23,000 light-years away in the constellation of Ophiuchus, and it's known to contain about 200,000 stars. What's unusual is that they're nearly all 20 to 80% the mass of our Sun; a surprisingly high ratio compared to the rest of the Milky Way. Astronomers estimate that M12 has ejected more than a million stars into the galactic halo, never to see them again.

View full article (http://www.universetoday.com/am/publish/past_globular_m12.html)
What do you think about this story? post your comments below.

GOURDHEAD
2006-Feb-08, 07:40 PM
The article seems to be more measured speculation, with which I agree, than hard science; however, it seems quite likely that the smaller stars would be most often scattered--there's more of them. We know too little about its history to be sure about the ratio of accretion to scattering or its initial formation.

Joff
2006-Feb-09, 05:47 PM
Does anyone have any insight on why low-mass stars would be scattered preferentially? It isn't obvious to me why any effect that scattered low-mass stars would not also scatter higher-mass stars.

eburacum45
2006-Feb-09, 07:10 PM
I suspect it is easier to scatter low mass stars than high mass stars in the same way that it is easier to scatter cats than cows (to use George's metaphor).

Joff
2006-Feb-09, 07:53 PM
The only mechanism I can think of is individual star-to-star encounters... The general mass of the galactic centre I would expect to have the same effect on big stars as small stars, with inertial mass being the same as gravitational mass...

George
2006-Feb-13, 12:24 AM
I suspect it is easier to scatter low mass stars than high mass stars in the same way that it is easier to scatter cats than cows (to use George's metaphor).
Gee, I used it twice and was worried it didn't work. You've not only got it, but have improved it from the original "it's easier to herd cattle, than cats". :) [It is a poplular metaphor in San Antonio, especially now during Rodeo. :)]