Heating the Solar Corona: A hot topic in plasma astrophysics

Prof. Christopher Watts

University of New Mexico

 

Abstract

The surface or photosphere of the sun is a blackbody with a temperature of about 7500 oC, and the basic mechanism that heats the sun, nuclear fusion, is well understood. However, there is a disconcerting paradox: The temperature of the solar atmosphere or corona starts to rise away from the surface to about 1,000,000 oC. Itís like walking away from a fire and you suddenly feel hotter. The energy that heats the corona is almost certainly stored in the magnetic field of the sun. There are two main competing models for how this energy is released: 1) Magnetic waves and 2) Tearing and reconnection of the magnetic field. Both models are probably valid in different regimes. In this talk, I will present an overview of the coronal heating paradox and the two heating models. Then Iíll talk about current research by plasma physicists, using both remote observations and laboratory simulations, focused on substantiating these models.