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Fraser
2004-Jul-08, 04:15 PM
SUMMARY: Astronomers with the Harvard Smithsonian Center for Astrophysics have discovered a pair of brown dwarfs circling one another, which should help answer some key questions about these objects. Are they large planets, failed stars, or something else entirely? One theory is that brown dwarfs form in clouds of interstellar gas, but they get ejected before becoming full stars. This pair of brown dwarfs, however, circle one another at 6 times the distance of the Sun and Pluto - their gravitational hold on one another is very tenuous. It's more likely they formed in a calm environment like regular stars.

What do you think about this story? Post your comments below.

om@umr.edu
2004-Jul-08, 05:18 PM
Interesting.

In the story Luhman asks, "Are brown dwarfs miniature failed stars, or super-sized planets, or are they altogether different from either stars or planets?"

He concludes that they were probably formed like other stars.

Dr. Alan P. Boss agrees that brown dwarfs formed in a fashion similar to that of stars like the Sun, and that brown dwarfs are "worthy of being termed 'stars,' even if they are too low in mass to be able to undergo sustained nuclear fusion."

Hopefully, quantitate measurements will reveal their source of luminosity.

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Jul-08, 06:23 PM
I had imagined that brown dwarfs [and super-Jupiter sized planets] formed more or less the same as red dwarfs and other smaller stars. The scenario that makes the most sense to me is that in a stellar nursery stars begin to form from denser areas that create a seed. When the biggest brightest stars ignite, they blow away loosely bound gas and dust from their neighbors, and the accumulation of material for the smaller stars halts at whatever size they are. We see something like this in the pillars in the Eagle nebula shot that Hubble took a few years back.

Concerning Dr. Manuel's query about the source of their luminosity, the article mentioned it. They are still cooling off and contracting from their heat of formation.

Littlemews
2004-Jul-08, 06:57 PM
If a star become self-sustain, it might blow away most of the nearby material by its strong solar wind (Who knows how strong it was while they become self-sustain), but if there is another nearby star was born in the same time(its companion), but had not enough material to help them because of the ordinary star blow away the material, should we consider this object as a fail star, but it still can orbit around its companion by mass exchange (only very small amount of the mass)?

Greg
2004-Jul-08, 09:51 PM
Once formed and separated from its stellar nursery, it is exremely unlikely that brown dwarfs will be able to gather additional fuel (hydrogen gas) during its lifetime to ignite stellar fusion.