APOD: 2004 November 26 - Magnetars In The Sky (original) (raw)

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2004 November 26

Magnetars In The Sky
Picture Credit: E. L. Wright(UCLA), COBE Project, CourtesyMSFC,NASA

Explanation: Indicated on this infrared image ofthe galactic center region are positions of candidate magnetars --believed to bethe strongest magnets in the galaxy. Classified by observers as Soft Gamma Repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs), these cosmic powerhouses are likelycity-sized, spinning, highly-magnetized neutron stars. How strong is a magnetar's magnetic field?The Earth's magnetic fieldwhich deflectscompass needles is measured to be about 1 Gauss, while the strongest fields sustainable in earthbound laboratories are about 100,000 Gauss. A magnetar'smonster magnetic fieldis estimated to be as high as 1,000,000,000,000,000 Gauss.A magnet this strong, located at about half the distance to the Moon would easily erase your credit cards and suck pens out of your pocket. In 1998, from a distance of about 20,000 light-years, one magnetar,SGR 1900+14 generateda powerful flash of gamma-rays detectedby many spacecraft.That blast of high-energy radiationis now known to have had a measurable effect on Earth's ionosphere.At the surface of the magnetar, its powerful magnetic field is thought to buckle and shift the neutron star crust generating the intense high-energy flares

Tomorrow's picture: edge-on Saturday

Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell(USRA)
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& Michigan Tech. U.