Stargazing - 04.13.12
When the Sun is low in the sky you sometimes can see three Suns: the real one and what looks like two smaller, fainter ones flanking it.
The extras are commonly known as sundogs, a name derived from the verb form of dog, which means “to follow.”
Star in a Bottle
In a laboratory designed to study nuclear explosions, astronomers are bottling a bit of starstuff. It lasts for only a fraction of a second, but that’s long enough to probe the conditions at the surface of a white dwarf—the final stage of life for the Sun and most of the other stars in the galaxy.
The experiments use the Z Machine at Sandia National Laboratories in Albuquerque. It takes current from a standard electric power grid, stores it, then compresses it. It discharges that power in a burst that lasts less than 100 billionths of a second. Yet in that brief time, it produces more than six times more energy than all the power plants on Earth combined.
Two years ago, astronomers from the University of Texas and physicists from Sandia began using the machine to study white dwarfs—the hot, dead cores of stars.
There’s still a lot to learn about white dwarfs. The Z Machine may help answer many questions by simulating conditions at a white dwarf’s surface.
The machine’s energy is released in a flash that shines into a cylinder about the size of a cigar. The chamber is filled with the same gases that are seen at the surfaces of white dwarfs. The flash heats the gases to millions of degrees, and instruments record what happens. That lets the astronomers compare the known conditions in the Z Machine to the unknown conditions at the surface of a white dwarf—learning more about real stars by capturing starstuff in a bottle.