Ultraviolet Coronagraph Spectroscopy: A Key Capability for Understanding the Physics of Solar Wind Acceleration

TL;DR

Ultraviolet coronagraph spectroscopy is crucial for understanding solar wind acceleration by enabling detailed plasma measurements in the extended solar corona, with next-generation instruments promising to address unresolved questions.

Contribution

This paper reviews past UV coronagraph spectroscopy achievements and proposes next-generation instruments to advance understanding of solar wind acceleration.

Findings

UV spectroscopy revealed key plasma properties in the corona.

Limitations of past instruments constrained understanding.

Next-generation tools can provide more comprehensive measurements.

Abstract

Understanding the physical processes responsible for accelerating the solar wind requires detailed measurements of the collisionless plasma in the extended solar corona. Some key clues about these processes have come from instruments that combine the power of an ultraviolet (UV) spectrometer with an occulted telescope. This combination enables measurements of ion emission lines far from the bright solar disk, where most of the solar wind acceleration occurs. Although the UVCS instrument on SOHO made several key discoveries, many questions remain unanswered because its capabilities were limited. This white paper summarizes these past achievements and also describes what can be accomplished with next-generation instrumentation of this kind.