There is a section on filaments at the very bottom of this page: http://rst.gsfc.nasa.gov/Sect20/A1.html http://rst.gsfc.nasa.gov/Sect20/A1.html I think that's

There is a section on filaments at the very bottom of this page: http://rst.gsfc.nasa.gov/Sect20/A1.html http://rst.gsfc.nasa.gov/Sect20/A1.html I think that's what he means by spokes.