SOLIS: reconciling disk-integrated and disk-resolved spectra from the Sun

TL;DR

This paper presents a method to relate high-resolution solar spectra with integrated spectra, enabling the inference of spatial features on the Sun and potentially other stars from disk-integrated observations.

Contribution

It introduces an updated approach to reconcile disk-resolved and disk-integrated spectra of the Sun, aiding the study of stellar surface features.

Findings

Developed a method to connect solar spectra at different resolutions.

Enabled inference of spatial distribution of solar features from integrated spectra.

Facilitated potential application to other stars' surface feature analysis.

Abstract

Unlike other stars, the surface of the Sun can be spatially resolved to a high degree of detail. But the Sun can also be observed as if it was a distant star. The availability of solar disk-resolved and disk-integrated spectra offers an opportunity to devise methods to derive information about the spatial distribution of solar features from Sun-as-a-star measurements. Here, we present an update on work done at the National Solar Observatory to reconcile disk-integrated and disk-resolved solar spectra from the Synoptic Optical Long-term Investigation of the Sun (SOLIS) station. The results of this work will lead to a new approach to infer the information about the spatial distribution of features on other stars, from the overall filling factor of active regions to, possibly, the latitude/longitude distribution of features.