First Observations of Coronal Hole Structure and Evolution Using Soho-Cds

Abstract

We report on initial observations of coronal holestructure and evolution by the Coronal Diagnostic Spectrometer (CDS) instrument on board the Solar and Heliospheric Observatory (SOHO). The data show that there is coronal activity on time scales of tens of minutes, manifested as brightenings at chromospheric network cell junctions in extreme ultraviolet (EUV) wavelengths. There are also significant differences in structure seen in different wavelengths in coronal holes. Finally, we show coronal hole EUV spectra and compare them to quiet-Sun spectra, also taken by CDS.