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Extra-solar Planet Imaged
bdb111 writes "European astronomers have taken what may be the first picture of an extra-solar planet. The possible planet orbits a brown dwarf star 230 light years away."
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Fantastic and cool. The only question I have is...where the hell is it? no where in the article could I find where to point a telescope to see it. I hope, for scientific verification, other astronomers have access to that information somewhere.
I am not an astronomer, but I don't know how visible a brown dwarf at 230 light-years, much less the possible planet, would be to most backyard telescopes. However, if you are a serious amatuer, with serious equipment, I'm there are star charts that list the location of 2M1207.
What's a little disappointing is that this planet is orbiting a brown dwarf, which isn't really a star...but its a start!
That has been a debated point for a while, and I guess it will continue to be until someone either vists one or sends a probe to vist one.
If you read the ESO press release you'll see that in addition to imaging it they've also taken spectra of it. The H-band spectrum they shows is similar to other sub-stellar objects, and it also shows fairly strong water absorption bands. This means that it's has to be fairly light. Evolutionary models have been run that predict that this object is about 5 times the mass of Jupiter.
Don't worry, most astronomers don't base their predictions on one image of something, they always follow it up with either multi-wavelength studies or spectral analysis, or both.
>What's a little disappointing is that this planet is orbiting a brown dwarf, which isn't really a star
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Arguing that it is not a type of star seems questionable. There is a grey area between giant planetary objects and tiny stellar objects. Brown dwarves share properties with both at various times in their evolution.
A Brown dwarf masses between 1 and 8 percent of our suns mass (which is a yellow dwarf). This mass is too small for gravity to produce high enough temperature and pressure in the core to sustain the fusion of hydrogen nuclei into helium 4. However this does not mean that fusion cannot occur. It also does not mean that the surface temperature of the body, or the luminosity of the body are not star-like at some point.
Gravitational contraction alone raises the temperature of the gas considerably. Though the surface temperature of a typical brown dwarf may be as low as 1000K, early in their career the heat generated by their gravitational collapse be be high enough to shine red for a short time. Larger brown dwarves may also have pressures and temperatures at the core sufficient for deuterium and tritium based fusion reactions. The resulting release of energy is futile as it is far too small to even temporarily balance or reverse the gravitationally induced contraction. They couldn't make a go of fusion on the professional circuit, but fusion is fusion. If star-hood is a nuclear club, their amateur standing should count
Yes, they are dim and cool. They can only continue to cool and eventually will radiate weakly in the radio spectrum, as Jupiter and other large gas plants do. However, at some points they may have pretty respectable surface temperatures (perhaps as high as 2500K). At the core they also may fuse some paltry amounts of deuterium and tritium.
On technical grounds this should justify calling them stars, if only briefly. On aesthetic grounds I also think these objects should be cut a bit of slack. The universe is cold and empty enough. Stripping these pitiful gas balls of star-hood entirely seems a bit too harsh.