Synthesizing Sun-as-a-star flare spectra from high-resolution solar observations

Abstract

Spatially resolved observations of the Sun and the astronomical sample size of stellar bodies are the respective key strengths of solar and stellar observations. However, the large difference in object brightness between the Sun and other stars has led to distinctly different instrumentation and methodologies between the two fields. We produce and analyze synthetic full-disk spectra derived from 19 small area field-of-view optical observations of solar flares acquired by the Swedish 1-m Solar Telescope (SST) between 2011 and 2024. These are used to investigate what can and cannot be inferred about physical processes on the Sun from Sun-as-a-star observations. The recently released Numerical Empirical Sun-as-a-Star Integrator (NESSI) code provides synthetic full-disk integrated spectral line emission based on smaller field-of-view input, accounting for center-to-limb variations and differential rotation. We use this code to generate pseudo-Sun-as-a-star spectra from the SST observations. ...

Published in A&A. 22 pages, 22 figures. Updated to reflect erratum: 10.1051/0004-6361/202554870]

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Cited by in corpus (5)

• Fine details in solar flare ribbons: Statistical insights from observations with the Swedish 1-m Solar Telescope
• Discovery of multi-temperature coronal mass ejection signatures from a young solar analogue
• On the center-to-limb variations of the He I 10 830 Å triplet
• The calm before the storm: High spatial resolution mosaic of active region NOAA 14274 at the onset of an X1.2 flare
• Chromospheric and photospheric properties of sunspots as inferred from Stokes inversions under magneto-hydrostatic and non-local-thermodynamic equilibrium