News FocusAstronomy

The Crab That Roared

See allHide authors and affiliations

Science  16 Aug 2013:
Vol. 341, Issue 6147, pp. 710-711
DOI: 10.1126/science.341.6147.710

You are currently viewing the summary.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution


When researchers with the AGILE gamma ray satellite first saw the readings 6 years ago, they didn't believe them. The Crab nebula, an 11-light-year-wide blob of glowing gas left over from an ancient supernova explosion, seemed to be spewing out enormous amounts of gamma radiation. Impossible, the scientists thought. The Crab was famously steady and quiet (so much so that astrophysicists used its emissions to calibrate their detectors), and AGILE was still in its hiccup-prone shakedown phase. So the scientists filed the data away as instrumental error. It was another 3 years before a chance observation revealed that the truth about the Crab nebula was more complicated than anyone had suspected.