Video: X-ray echoes

updated 2/11/2009 1:28:17 PM ET 2009-02-11T18:28:17

One of the most dramatic — and violent — reality shows is unfolding not on TV, but 30,000 light-years away in the constellation Norma.

There is a corpse, the remains of a truly gigantic star with 40 times or more mass than our sun, but it is hardly at rest. In a resurrection that has captivated the astronomical community, the body, known as SGR J1550-5418, is periodically showering the cosmos with blasts of radiation encompassing every highway of the electromagnetic spectrum from gamma rays to radio waves.

It was once known as an anomalous X-ray pulsar, meaning it blasted out X-rays on a regular basis, but scientists didn't know why. They suspected it was a magnetar, the highly magnetized and collapsed remains of star so dense that even electrons have broken down.

More recently, astronomers discovered that 5418 repeatedly flares in gamma rays as well, possibly due to some serious torture of its magnetic field lines.

"This is one of the extreme laboratories in nature. We could not produce this kind of extreme condition on Earth," Chryssa Kouveliotou, an astrophysicist at NASA's Marshall Space Flight Center in Huntsville, Ala., told Discovery News.

A pair of gamma ray telescopes picked up 5418's flares in October. It quieted for three months, then burst back to life with renewed vigor on Jan. 22. Astronomers logged more than 100 flares in one 20-minute period. The most powerful flares blasted out in split seconds as much energy as our sun produces in 20 years.

Scientists believe the secret is in the magnetism.

Slideshow: Month in Space: January 2014 Magnetars' magnetic fields are a million billion times more powerful than Earth's, which measures 0.5 gauss. The sun's magnetic field is one gauss; a sunspot about 1,000 gauss. A magnetar's field weighs in at 1,000,000,000,000,000 (10 to the 15th) gauss, also known as one peta-gauss. The most powerful of all belong to magnetars like 5418, known as a soft gamma ray repeater (SGR).

"The SGRs are the most highly magnetized objects in the universe," said astronomer Donald Figer with the Rochester Institute of Technology in New York. "We don't know why."

Scientists are hoping to solve the mystery by studying 5418 and other SGRs and comparing the real observations with what has been generated in computer simulations. Scientists theorize that the magnetic fields could have been generated by an internal dynamo as the star collapsed.

Or perhaps a star's previously existing magnetic field lines were scrunched as the star compressed into a 10-mile-wide neutron star.

"We would like to know how it is that such strong magnetic fields are generated and how the energy is transferred out to make the outburst that we see today, said astronomer Jules Halpern at Columbia University in New York.

"The instruments we're using now are very effective, but the stars have their own schedule," he added. "What's important is to have instruments that constantly monitor for outbursts like this."

© 2012 Discovery Channel


Discussion comments


Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments