[LINK] "Twin Suns May Spell Disaster"

[rfmcdonald]

At Centauri Dreams, Paul Gilster raises the example of Star Wars's Tattoine, with its two suns, when he lets us know that recent research suggests that although planets could form around closely-orbiting binary stars, their lifespan may be quite limited.

Imagine two stars similar to the Sun in size and about as old as the Sun when life first evolved on the Earth. They’re possessed of strong magnetic fields and giant spots, the result of their fast spin, and the magnetic fields, in turn, drive powerful stellar winds that slow the stars and pull them closer together over time. Now things get tricky, for the new work suggests that the gravitational influences of the stellar pair continually change as the stars approach each other, causing planets and other objects circling the stars to experience collisions.

Says Marc Kuchner (NASA GSFC):

“These kinds of systems paint a picture of the late stages in the lives of planetary systems. And it’s a future that’s messy and violent.”

Indeed. And the evidence from [NASA's Spitzer space telescope] seems tight. The instrument can see the glow of hot dusky disks around three tight binary systems matching this description. The thinking is that the dust found here would normally have dissipated from stars at this level of maturity. Something, in other words, is causing fresh dust to be created, implying a chaotic process. Planetary collisions are the most likely candidate.