M
mikeemmert
Guest
Dear All:<br /><br />Space.com has presented this story about the dust discs of other stars. It turns out several of them have something in common with the Sun.<br /><br />The Kuiper Belt in our own solar system has an edge (see Edge of the Classical Belt link on the left hand column of links) at about 47 A.U. So do many of the other stars examined in the Space.com article.<br /><br />Could another star have carved out the edge of the Edgeworth-Kuiper Belt? The evidence is slim, but tantalizing. There is Buffy, which has a circular orbit around the sun at a distance that puts it right at the edge of the Kuiper Belt but has an inclination of 46.7 degrees. Then there's Sedna which is not part of the Kuiper belt. And there is the fact that the aphelia of a lot of long-period comets cluster at 50,000 A.U.<br /><br />But is this hypothetical Nemesis of the Sun still there? The serious scientists who proposed that figured it could have receded to as much as 1.5 A.U. from the sun, which means a passing star could have ripped it away. Alternatively, many of the observations can be explained by some massive object on a parabolic trajectory that never orbited the Sun. Or, there might be some other explanation altogether.<br /><br />Here's a brand new thread on the Death Star. Hopefully the material that belongs in Free Space or Phenomenon will stay in those realms. <img src="/images/icons/smile.gif" />