PDA

View Full Version : Magnetar observations...



RoboSpy
2004-Sep-15, 02:08 PM
It had never occurred to me until just now, but how do astronomers tell the magnetic field strength of an astronomically far-away object like a magnetar? Surely it's not a direct observation of the field, since it would be drowned out by the fields of the Earth and Sun (I assume) and would be terribly weak at this distance anyway. So what method do they use to measure a really far-away magnetic field?

ToSeek
2004-Sep-15, 02:21 PM
Using data from two satellites, Kouveliotou and her team determined the strength of the star's magnetic field by measuring the speed at which its rotation is slowing -- an effect believed to be caused by the star's powerful magnetic field.

- http://www.sciencedaily.com/releases/1998/05/980521080832.htm