Ever wonder what happens when a powerful stellar jet from a young star collides with giant clouds of gas and dust? Astrophysicists recently recreated this cosmic event in a laboratory. And it only took a multitrillion-watt laser capable of delivering more power than exists in the entire U.S. power grid.
The Omega laser at the University of Rochester's Laboratory for Laser Energetics in New York is one of the top three lasers available. Scientists conducted this experiment to compare the lab results with both computer models and telescope observations of a real-life stellar jet, or the outpouring of matter from a fledgling star. This is the first time a study has collected new astronomical data from a laboratory simulation.
Here’s how the experiment went down: First, the football field-sized Omega laser fired for a millionth of a second at a small cylindrical can called a Hohlraum. Then the vaporized can sent radiation slamming into a piece of titanium the size of a marble and the titanium almost instantaneously heated into a plasma similar to what exists in stellar jets. And finally, the plasma struck a tiny sphere of plastic embedded in foam, which stood in for interstellar gas clouds.
Pat Hartigan is an astrophysicist at Rice University in Houston, Texas, and lead author of this new research. As he told reporters, "Ours is the first study to investigate what happens when jets run into obstacles along their paths, and the first to have a strong enough laser to properly scale the shock waves in a jet to the astrophysical case."
And that’s not all. Physicists now hope to trigger a laboratory thermonuclear fusion reaction similar to what takes place on the sun. Hartigan and fellow astrophysicist Adam Frank compared the Omega laser experiment to real-life stellar jet collisions because of mathematically equivalent ratios among the matter densities. Apparently, the behaviors of giant star entities can be the same as a lab experiment as long as the density ratios are the same.
The experiment showed scientists how interstellar clouds and gas clumps can partially deflect stellar jets. But there was a surprise in store for the researchers. An experimental jet in the lab burrowed into the plastic sphere and lifted entire pieces off, rather than simply vaporizing the target pieces. Researchers feel that this discovery can explain observations of how real-life stellar jets could drag along easily destroyed molecular hydrogen from clouds.
Experts hope that stellar jets might reveal themselves to be thermostats for stellar nurseries by regulating star birth. As Frank notes, “maybe something like the feedback from many jets running into each other or their environment keeps the cloud from collapsing on itself [and forming more stars].”
The next experiment with the Omega laser is scheduled for Feb. 26, 2010.