Most of the information that we get from the Sun comes from the light it emits. Analyzing its spectral content, polarization, spatial distribution, temporal variability, etc, informs us on such diverse characteristics of the Sun as its temperature, densities, composition, magnetic field, dynamics and activity. During this talk, I will review the mechanisms by which the Sun produces light and we will see what the solar emission tells us about our star. Focusing on solar irradiance, I will present the current state of modeling and discuss the main hot topics and controversies of this research field.
This seminar is the eleventh of a series of seminars on the basics of solar and heliospheric physics, aimed at our ROB, IASB and RMI colleagues who have a sound knowledge of physics and mathematics but never had a formal education in solar and heliospheric physics. These talks will provide an overview of the most important aspects without going in too much detail. References for further reading are provided.