A Century of Imaging the Corona and Solar Wind

95 years ago, Bernard Lyot introduced the solar coronagraph, a device to image theSun’s corona even without a total solar eclipse.

That instrument launched a century of coronagraphy that has only accelerated: from ground-based instruments tospaceborne coronagraphs and, more recently, multi-viewpoint constellations and wide-field systems that capture the entire inner heliosphere as an evolving, three-dimensional medium.

Image data, which trace large-scale density structures across broad volumes of space, complement the more physically complete but locally restricted data available from in-situ probes, and reveal physical context that can be achieved in no other way.

The measurements themselves are quite challenging, as demonstrated by many recent advances in instrument design including those of Metis, ASPIICS, and PUNCH.

In this colloquium, I’ll recap the physics of these instruments and the evolving solutions used to create ever-better imagery of the heliosphere and its origin, and highlight some recent results from the PUNCH mission, which uses this technology to image the entire inner solar system once
every four minutes.

Local contact person: Silvano Fineschi