A Catalog of Solar Flare Events Observed by the SOHO/EIT

Abstract

We have compiled a catalog of solar flares (SFs) as observed by the Extreme ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO) spacecraft and the Geostationary Operational Environmental Satellites (GOES) spacecraft over a span from 1997 to 2010. During mid-1998, the cadence of EIT images was revised from two images per day to 12 minutes . However, the low temporal resolution causes significant data gaps in capturing much of the flaring phenomenon. Therefore, we monitor possible errors in flare detection by flare parameters such as temporal overlap, observational wavelength, and considering full field-of-view images. We consider the GOES flare catalog as the primary source. We describe the technique used to enhance the GOES detected flares using the extreme ultraviolet image captured by the EIT telescope. In order to detect brightenings, we subtract the images with a maximum cadence of 25 minutes. We have downloaded and analyzed the EIT data via the Virtual Solar Observatory. This flare data set from the SOHO/EIT period proves indispensable to the process of the SF predictions as the instrument has covered most of Solar Cycle 23.