Stardust evidence points to planet collision

[SteveZilla]

Stardust evidence points to planet collision.

 

Wow, talk about movies coming true.

[DusterBoy]

Re: Stardust evidence points to planet collision

 

Wow. That's just . . . amazing.

[Nolgroth]

Re: Stardust evidence points to planet collision

 

Big badda boom.

[Kristopher]

Re: Stardust evidence points to planet collision

 

300 million light years?

 

So this is in which galaxy, exactly?

[Nolgroth]

Re: Stardust evidence points to planet collision

 

And has that dust had time to form a new planet I wonder. Not a physicist so I really have no clue how long it takes for planet formation. Or even if it would be possible.

[Nyrath]

Re: Stardust evidence points to planet collision

 

300 million light years?

 

So this is in which galaxy, exactly?

The article is incorrect. BD +20°307 is 300 light years away, not 300 million. The star is 300 million years old, which is probably where the reporter made their mistake.

http://en.wikipedia.org/wiki/BD_%2B20%C2%B0307

http://jumk.de/astronomie/exoplanets/bd-20-307.shtml

 

However, this would of course be an ultra-dramatic setting for the climax of your Star Hero campaign. Can your players finish their mission on Planet A before Planet B smacks into it? Imagine the tension, as Planet B grows larger in the sky, and the earthquakes start.

[austenandrews]

Re: Stardust evidence points to planet collision

 

"My darling, I wish I could call Venus from the sky and put it in your hand like a jewel!"

 

"Dearest, are you still wearing that Wish Ring?"

 

"Oh crap."

[Cancer]

Re: Stardust evidence points to planet collision

 

Grr, it's not in the Sep 20 ApJ table of contents. Now I have to see if I can find it.

 

EDIT: OK, it's a arXiv preprint, accepted for publication in the 10 Dec 2008 ApJ. Now let's see what it says.

 

The system has a lot of dust in it. The infrared luminosity is large, and that means lots of cool, little bits strewn about: that's the way you get lots of IR.

 

OK, the system is a tight binary of quite similar, vaguely solar-type main sequence stars. (The orbital period is 3.5 days, circular, probably inclined by about 30 degrees, they don't eclipse, no starspots found. They quote a G0 spectral type. The stars rotate synchronously and the X-ray data they did jibe with that. It's unclear what the age is; the lower metallicity and lithium abundances suggest old, the space motion is more typical with that of younger stars but there do exist old ones with that sort of space motion. "Old" here means a couple billion years or more; "young" means no more than 50 million or so.

 

Then ... RUNNING WITH THE ASSUMPTION that it's old ... they ask where all the dust came from.

 

(In general, it's not at all surprising to find lots of dust around young stars. They haven't had time to get clear of the dust cloud in which they form. By contrast, old main sequence stars had long lost nearly all remnants of that dust. Dust gets lost over time through several mechanisms, so if an old star has dust with it then the implication is that there is a source of dust in that system.)

 

There is lots more dust there than just about any other nearby comparable star, and the dust has a narrow range of temperature. They suggest that a relatively recent collision of a couple of terrestrial planets could do it. This isn't exactly a new idea, apparently; I need to read one of their references which they cite for the suggestion.

 

I'm not yet convinced. As they themselves point out, if that conclusion is accepted, then it's also the first indication of existence of terrestrial planetary objects orbiting tight binary stars. That makes me sit back and think a bit.

[Kristopher]

Re: Stardust evidence points to planet collision

 

The article is incorrect. BD +20°307 is 300 light years away, not 300 million. The star is 300 million years old, which is probably where the reporter made their mistake.

http://en.wikipedia.org/wiki/BD_%2B20%C2%B0307

http://jumk.de/astronomie/exoplanets/bd-20-307.shtml

 

Thank you for looking it up. Makes a lot more sense now.

 

However' date=' this would of course be an ultra-dramatic setting for the climax of your Star Hero campaign. Can your players finish their mission on Planet A before Planet B smacks into it? Imagine the tension, as Planet B grows larger in the sky, and the earthquakes start.[/quote']

 

Indeed.