Astronomer: Earth-Like Planets Are Common, But Stars Have Eaten Many

[Swede]

His hypothesis: the heavy elements came not from the interstellar medium, but rather from the remains of rocky planets that once orbited the stars back in their younger days. For a study he presented at the Royal Astronomical Society meeting in Scotland this week, he looked at 146 white dwarfs that showed calcium pollution in their atmosphere, and which haven’t hung around near the interstellar medium anytime in the recent past. If the heavy elements in these stars had come from the medium, he argues, it would’ve sunk to the core long ago—it wouldn’t be dancing around with the light elements in the upper atmosphere. Ruling out the interstellar medium, Farihi says there are two possibilities: the debris could come from an asteroid belt similar to our own, which essential represents a planet that didn’t form, or the pieces of a shattered planet

If he’s right it could be further evidence that rocky planets are rather common around stars like our sun. The proportion could be even greater than 20 per cent, as some planetary systems might be entirely destroyed and leave no trace rather than leaving behind a debris ring to pollute their parent star

http://blogs.discovermagazine.com/80beats/2010/04/13/astronomer-earth-like-planets-are-common-but-stars-have-eaten-many/

[WheelWalker]

1. Stone soup? Reminds me

of that story from my youth.

[Ian David]

2. See prior thread: Mitch's Mystery Star, Curiouser and Curiouser

Mitch's Mystery Star, Curiouser and Curiouser
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=228x65473

[ashling]

3. Mmmmm, earth planets - tastee!