Added 1 new A* page:A couple recent bits of space news:|
- NASA’s Chandra Captures X-Ray Echoes Pinpointing Distant Neutron Star (NASA): A neutron star is what you get when a star that isn't *quite* massive enough to flaunt the normal rules of matter and collapse into a single point in space—a black hole—collapses: an incredibly dense spinning ball! This particular neutron star, 30,700 light years away, on the other side of the galaxy, is ripping material off of its binary partner and throwing it out into space in rings, which served as an array of mirrors, reflecting X-rays from the neutron star in our direction, and because the travel time differed slightly depending on the displacement of the "mirror," this allowed scientists to calculate the neutron star's distance from us pretty precisely, essentially by triangulation. Anyway the part I thought was particularly interesting about this star was this: "This new distance estimate means that Circinus X-1 is inherently much brighter in X-rays and other types of light than some scientists previously thought, and indicates that the star system has repeatedly passed a key threshold for brightness where the outward pressure from radiation by the system is balanced by the inward pull of gravity. This behavior is something astronomers generally see more often in systems containing black holes than in systems like Circinus X-1 that contain a neutron star. The researchers also determined that the speed of the jet of high-energy particles produced by the system is at least 99.9% of the speed of light. This extreme velocity is usually associated with jets produced by a black hole." So this neutron star is behaving somewhat like a black hole, which is "unusual."
- Rosetta spies cometary sinkholes (BBC): The ESA's spacecraft orbiting comet 67P has spotted sinkholes—a different kind of black hole, if you will : ), although these are actually the source of some of the spectacular jets of gas and particles that have been streaming off the comet with increasing intensity as it nears its closest approach to the Sun: sunlight strikes the newly revealed ices on the walls of the holes, and they boil right off. Just as sinkholes on Earth are due to subterranean erosion, so can the innards of a comet wear away, it appears; probably another part of the boiling off going on as the comet heats up. And conveniently, these holes, up to 200 meters deep by 200 meters wide, allow Rosetta to look into the interior of the comet for the first time! 67P will reach its closest point to the Sun next month, heating up all the while.