Basic Solar Physics Seminars (6/13) - Observations and Instruments

by David Berghmans

Meridian Room

Meridian Room


Overview of observational methods and instruments: EUV and X-ray imagers, coronagraphs, heliospheric imagers, radiometers.

As the solar corona is one of the prime research topics of the SIDC, we will further explore where Matt West left the subject in his basic seminar of November 22, 2017.Except at times of solar eclipse, the solar corona is not (or hardly) visible without specialised telescopes on space platforms. We will focus on instrumental aspects of two types of telescopes in which "Belgium" is playing a pioneering role: EUV imagers and coronagraphs. Both type of instruments show the same solar corona, yet the images look different in many ways. Why is that?

Despite decades of analysis and modelling, crucial insight is missing in the gap between the capabilities of both instruments. At a few million km from the solar surface, the magnetic structuring of the corona loses its dominance over the gas pressure, and the typical corona topology fades into the solar wind. Exactly this crucial region is where both EUV imagers and coronagraphs up till now have delivered poor data and where some of the remaining big solar questions are waiting to be addressed: How does the structuring and dynamics of the corona drive the solar wind? From which part on the Sun is the solar wind at Earth originating?

The talk will close with an outlook on the two main developments of SIDC currently in the space-shipyards: the ASPIICS coronagraph on PROBA-3 and the EUI telescopes onboard Solar Orbiter. Thanks to unprecedented mission concepts, both instruments are expected to bring us 'closer' to understanding the solar corona than ever before.

This seminar is the sixth 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.