Astronomy: High-Energy Surprises in 'Constant' Crab Nebula

Hubble Space Telescope Astronomy Poster Print - A Giant Hubble Mosaic of the Crab Nebula - 24 X 24

Hubble Space Telescope Astronomy Poster Print


The Crab Nebula is considered a cornerstone of high-energy astrophysics. Astronomers are measuring its pulse.
ScienceDaily (Jan. 13, 2011) — The combined data from several NASA satellites has astonished astronomers by revealing unexpected changes in X-ray emission from the Crab Nebula, once thought to be the steadiest high-energy source in the sky.

"For 40 years, most astronomers regarded the Crab as a standard candle," said Colleen Wilson-Hodge, an astrophysicist at NASA's Marshall Space Flight Center in Huntsville, Ala., who presented the findings Jan. 12, 2011 at the American Astronomical Society meeting in Seattle. "Now, for the first time, we're clearly seeing how much our candle flickers."