Winking Star Decoded as Root of Planetary System 40
sam1am points out a New York Times report on a recent paper published in Nature about the formation of planetary systems. A binary star system surrounded by a protoplanetary disc was observed over a period of six years by scientists at Wesleyan University. The orbit of the stars around each other caused changes in illumination from within the disc and allowed the researchers to learn a great deal about its composition. Some of the basic data is posted on the university's site. An animation of the system is also available. From the NYTimes:
"'This is the first step in going from smoke particles to macroscopic things like planets and asteroids,' Dr. Herbst said in an interview, noting that these grains were about the same size as those found in many meteorites. Observing starlight reflected from these grains, he said, represented a rare opportunity to study the structure and chemical properties of material in the inner parts of another planetary system."
Wow, those stars are moving fast (Score:5, Interesting)
Now the question is how this disc formed around two stars with such high inclinations relative to it. The typical nebular collapse theory isn't going to work here due to the conservation of angular momentum. Could one of the stars have traveled through a dense nebula or had a multi-body interaction with a recently formed system thus starting this odd system? And if so then wouldn't these results be of a hybrid system and not necessarily representative as the missing gap that the article claims? With two stars with such high inclinations, high velocities, and large major axes, no inner planet is ever going to form and the source of this dust probably isn't from a single nebular collapse. I certainly don't think it has a definitive connection to our solar system formation.
1mm objects at 2400 light years (Score:5, Interesting)
Of course now the bible literalists can jump up and say "see we are made from dust" but hell that can only lead to interesting conversations....
Re:1mm objects at 2400 light years (Score:5, Interesting)
Second, the author's results depend on whether their particular model geometry for the binary system + disk is correct.
And third, in their Nature paper they argue that they most likely are biased towards the smallest grains that make up the circumbinary disk, and that the bulk of the disk may be in even larger grains ('pebbles'). For the same amount of occultation, that would require much more mass (see first point). I wonder whether that wouldn't result in an insane mass for the disk ... they don't discuss this ;-)
Re:Earth-like?? (Score:5, Interesting)