Their continuing analytic work on the effect of magnetic shear on plasma dynamics will be combined with numerical calculations on heating processes in the Sun, and compared with extensive datasets from solar observatories and satellites. The NASA grant provides for Evergreen students to contribute to new computations and data analysis, on campus and in visits to HAO, in collaboration with colleagues from Boulder, Oslo, and London. Zita continues to welcome new students to her research team, many of whom start by taking her spring Astronomy and Cosmologies program. Many stars ring with sound waves. Sound waves in a star are basically compressions and expansions of the stellar material, a hot ionized gas called plasma.
Astronomers can tell stars are ringing when their brightness varies in characteristic ways.
Astronomers are pretty sure that roAp sound waves are somehow connected with the stars' strong magnetic fields, because they have the same spatial symmetry, and because Ap stars don't ring unless they have a strong magnetic field. Zita has an idea about how the magnetic fields of roAp stars could cause their sound waves. The twisted magnetic fields have an equilibrium shape, or minimum energy configuration. At rest, the magnetic field would maintain its shape, rather like a slinky toy distorted into a spherical shape. If you stretch and release a slinky toy, it oscillates near its minimum energy state.