Research progress on coronal extreme ultraviolet waves

Soho Eit Observations of Extreme-ultraviolet “dimming” Associated with a Halo Coronal Mass Ejection

A solar flare was observed on 1997 April 7 with the Soft X-ray Telescope (SXT) on Yohkoh. The flare was associated with a “halo” coronal mass ejection (CME). The flaring region showed areas of reduced soft X-ray (SXR) brightness—“dimmings”—that developed prior to the CME observed in white light and persisted for several hours following the CME. The most prominent dimming regions were located ne...

The quiet Sun extreme ultraviolet spectrum observed in normal incidence by the SOHO coronal diagnostic spectrometer

The extreme ultraviolet quiet Sun spectrum, observed at normal incidence by the Coronal Diagnostic Spectrometer on the SOHO spacecraft, is presented. The spectrum covers the wavelength ranges 308–381 Å and 513–633 Å and is based on data recorded at various positions on the solar disk between October 1996 and February 1997. Datasets at twelve of these ‘positions’ were judged to be free from acti...

Can Trace Extreme-ultraviolet Observations of Cooling Coronal Loops Be Used to Determine the Heating Parameters?

Recent analysis of relatively cool (∼1 MK) active region loops observed with TRACE has suggested that these loops have been heated impulsively and are cooling through the TRACE bandpasses. In this Letter we explore the evolution of cooling loops to determine if the TRACE EUV observations can be used to determine the magnitude, duration, and location of the energy release. We find that the evolu...

An Extreme Ultraviolet Spectrometer

A concept and preliminary design of an Extreme Ultraviolet (EUV) spectrometer is presented. The spectrometer is based on a gas ionization chamber and an advanced eight-electrode electron focusing system to form a narrow electron beam on a photodiode aperture. The design is modeled with the SIMulation of IONs (SIMION) tools and shows the ability to scan through the spectral range of 20.0 – 40.6 ...

Coronal Waves, Shock Formation and Coronal Mass Ejections