The narrow, sharp-edged and slightly off-centre rings of dust that surround some stars may be the result of interactions between gas and dust, rather than the gravitational effects of planets, as previously proposed. The finding, published in this week’s Nature1, could dramatically affect estimates of the number of exoplanets hiding in such stellar systems.
Many nearby stars, especially young ones, are surrounded by disks of dust debris, which orbit the stars at distances roughly equivalent to that at which Pluto orbits the Sun. Embedded in some of those disks are dust rings that have unexpectedly crisp edges and slightly lopsided orbits. Wladimir Lyra, an astrophysicist at the California Institute of Technology in Pasadena and co-author of the latest study, says that researchers have often attributed such irregularities to the gravitational tugs of exoplanets that are too dim to be observed directly. More.
It will be interesting to see whether the 60 billion habitable planets hype gets scaled back, if this finding holds up.
Or is that just a big number everyone likes? Will it be ramped up to “trillions” for effect? Gonzalez, where the heck are you?
Note: Evolution News & Views has just published a brief backgrounder on what really happened at Iowa State University, revealing that Gonzalez was not denied tenure because he was incompetent or controversial. He stuck to traditional parsimonious assumptions in an environment where—had he said there was an infinite number of universes in which each of us has an exact double—he would have been considered mainstream.
Sorry, Iowans, your taxes support what has got to be one of the world’s bigger fruitcakes. Maybe Ball U will show more sense.