Solar Origin of the Interplanetary Magnetic Field

Norman F. Ness, John M. Wilcox
1964 Physical Review Letters  
Hard copy (HC) U n i v e r s i t y of C a l i f o r n i a Microfiche ( M F) Space S c i e n c e s L a b o r a t o r y B e r k e l e y , C a l i f o r n i a ff 653 July 65 Direct measurements of t h e i n t e r p l a n e t a r y magnetic f i e l d . a t 1 A.U. have r e c e n t l y been made by a n experiment' conducted on t h e I n t e r p l a n e t a r y Monitoring P l a t f o r m (IMP-1) The 63 kg s p i n s t a b i l i z e d s a t e l l i t e w a s launched on Nov. 27, 1963 i n t o a h i g h l
more » ... i n t o a h i g h l y e c c e n t r i c o r b i t w i t h a g e o c e n t r i c apogee of 197,616 km. and a n o r b i t a l p e r i o d of 93.5 h o u r s . The Sun-Earth-apogee a n g l e w a s i n i t i a l l y 25O w e s t o f t h e Sun and i n c r e a s e d a p p r o x i m a t e l y 1°/day due t o t h e E a r t h ' s h e l i c o e n t r i c motion. S u c c e s s f u l t r a n s m i s s i o n o f s c i e n t i f i c data c o n t i n u e d f o r 180 d a y s u n t i l May 30, 1964 when t h e Sun-Earth-apogee a n g l e had i n c r e a s e d t o 2 0 1 ' . The i n t e r p l a n e t a r y d a t a is based on t h e a v e r a g e magnetic f i e l d computed e v e r y 5 . 4 6 m i n u t e s u s i n g 1 2 -s u c c e s s i v e d a t a t r a n s m i s s i o n s a t 2 0 . 5 second i n t e r v a l s . The 9 -_ a b s o l u t e u n c e r t a i n t y of t h e d a t a is l e s s t h a n 0 . 2 5 Y ( l Y = gauss) . T h i s l e t t e r p r e s e n t s t h e i n i t i a l r e s u l t s of a d e t a i l e d comparison o f t h e s e i n t e r p l a n e t a r y magnetic f i e l d measurements w i t h s o l a r magnetograph o b s e r v a t i o n s of t h e p h o t o s p h e r i c m a g n e t i c f i e l d s as m n a s l~r e d at t h e Mt. Wilson Ohservatnrv-' --. 0 e -1 . # i i m" 0 / 7 -/ e /
doi:10.1103/physrevlett.13.461 fatcat:6572jkotyzfuneejjeykdtad34