Coronal Imaging with the Solar UltraViolet Imager

TL;DR

This paper demonstrates that the Solar UltraViolet Imager (SUVI) can effectively image the solar corona at unprecedented heights in EUV wavelengths, extending beyond the nominal field of view.

Contribution

The study shows SUVI's capability to image the solar corona beyond three solar radii, revealing EUV signals outside its standard imaging area.

Findings

SUVI can image the corona to larger heights than previously achieved.

EUV signals are detectable beyond three solar radii.

SUVI's dynamic range and sensitivity are sufficient for extended coronal imaging.

Abstract

We investigate the coronal imaging capabilities of the Solar UltraViolet Imager (SUVI) on the Geostationary Operational Environmental Satellite-R series spacecraft. Nominally Sun-pointed, SUVI provides solar images in six Extreme UltraViolet (EUV) wavelengths. On-orbit data indicated that SUVI had sufficient dynamic range and sensitivity to image the corona to the largest heights above the Sun to date while simultaneously imaging the Sun. We undertook a campaign to investigate the existence of the EUV signal well beyond the nominal Sun-centered imaging area of the solar EUV imagers. We off-pointed SUVI line-of-sight by almost one imaging area around the Sun. We present the details of the campaign conducted when the solar cycle is at near the minimum and some results that affirm the EUV presence to beyond three solar radii.