The Signature of Flares in VIRGO Total Solar Irradiance Measurements

TL;DR

This study analyzes VIRGO TSI data to estimate the energy emitted by X-class solar flares, revealing systematic errors and the ratio of X-ray to total luminosity, advancing understanding of solar flare energetics.

Contribution

It introduces a method using summed-epoch analysis on VIRGO data to estimate flare energy and characterizes systematic errors affecting high-frequency photometry.

Findings

Estimated mean radiative energy of X-class flares.

Detected and characterized systematic errors in TSI data.

Found the X-ray to bolometric luminosity ratio to be about 0.01.

Abstract

We use Total Solar Irradiance (TSI) measurements from the VIRGO (Variability of solar IRradiance and Gravity Oscillations) instrument on board SOHO to obtain preliminary estimates of the mean total radiative energy emitted by X-class solar flares. The basic tool is that of summed-epoch analysis, which has also enabled us to detect and partially characterize systematic errors present in the basic data. We describe these errors, which significantly degrade the photometry at high frequencies. We find the ratio of GOES 1-8\{AA} luminosity to total bolometric luminosity to be of order 0.01.