Wednesday Colloquia

Probing convection and magnetic dynamos deep within stars

by Prof. Juri Toomre (JILA & Department of Astrophysical and Planetary Sciences, University of Colorado Boulder)

Wednesday, December 9, 2015 from to (Asia/Kolkata)
at TIFR Mumbai ( AG-66 )
Description
The rich magnetism displayed by many stars, including our sun, 
must have their origin in dynamo action proceeding within their 
convection zones involving highly turbulent flows influenced by 
rotation and stratification.  The striking advances in seismic probing 
of stars is providing guidance about rotation states, and possibly of 
magnetism, deep within a range of stars. This is complemented 
by supercomputing advances that now permit 3-D global simulations 
of solar and stellar convection to study the nature of magnetic 
dynamo action and differential rotation that can be achieved by 
complex flows involving a hierarchy of scales and patterns.  In 
sun-like stars, the resulting magnetic fields can exhibit remarkable 
large-scale structure involving wreaths, along with temporal flips 
and even cycles.  In more massive stars with core dynamos, 
super-equipartition magnetic fields with mega-gauss strengths can 
be realized, and these have implications for intense fields in later 
stages of evolution. These overlaps in observations and computational 
theory make for a period of major adventures in stellar astrophysics.