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."
Other kinds of winks reveal planets (Score:3, Informative)
(2) Eclipsing transits occurs when the planet passes edge on across the face of the star. The star will dim for a few hours. Even in our solar system transists of Mercury and Venus only happen a few hours each century, so they are hard to catch. I think think they've found about ten planets this way.
(3) Gravitational lensing occurs when a solar system eclipses another star about twice as far away. There are temporary brightenings of the occluded star when its planet crosses the occluded star. This can see planets as small as earth. I think they've found about five planets this way.
In 2009 the Kepler space probe will stare unblinking at the same patch of sky for months at a time. It is mainly seeking eclipsing transists but could catch lensing too. It will watch several hundred thousand stars simultaneously and hopefully capture few hundred planets.