HL Tauri: A solar system in the process of formation

[smartcooky]

Someone posted this on ISF (formerly JREF). I thought it was worth repeating here.

Truly awesome!!!


This is an image of the star HL Tauri (450 LY away) taken with the
European Southern Observatory's ALMA sub millimetre telescope. It shows
the star during formation (which has been under way for about a million
years) with the proto-planetary disc and planets being formed.




Here is a scale comparison with our Solar System



More info
http://www.eso.org/public/usa/news/eso1436/

[AstroBrant]

Thanks for showing that. I didn't realize we could get such a great picture of an accretion disk. It's amazing to see how the planets are sweeping up the matter along their orbits. Interesting distribution of planets. I would have expected to see some spiral structure, but not a hint of it from what I can tell.

The two darkest rings seem awfully close together for what must be Jovian planets. Maybe they will combine or form a binary system.

[ka9q]

I think even a Jupiter-sized planet would be much too small to be seen at this scale. The dust bands in the accretion disk are probably formed by gravitational resonances from those planets, just as the bands in Saturn's rings are caused by gravitational resonances from its moons.

There isn't necessarily a planet in each dark band, but I'm sure somebody is solving for the possible planets and masses that could produce what we see.

[ka9q]

The two darkest rings seem awfully close together for what must be Jovian planets. Maybe they will combine or form a binary system.

Remember the current theory for the moon's formation: another planet, named Theia, formed in the same orbit as the earth but at one of its stable Lagrange points (L4 or L5). These points are stable only for small masses; eventually Theia grew large enough to leave L4 or L5 and hit the earth.