2 Instruments and data selection

The radio type II observations were obtained with the radio spectral polarimeter of the Astrophysical Institute Potsdam (Mann et al. [1992]). The instrument consists of sweep-frequency spectrographs in the ranges 40-90, 100-170, 200-400 and 400-800 MHz, with a sweep rate of 10  $\rm s^{-1}$. The dynamic spectrograms were digitally recorded. Here, we present the spectra of 21 type II bursts observed in 1997 after background subtraction. Bright stripes appearing at a constant frequency are due to terrestrial disturbances.

The joint ESA/NASA Solar Heliospheric Observatory (SOHO) mission offers a unique set of spacebased solar observations (Fleck et al. [1995]). The EIT onboard SOHO provides line observations at several temperatures. We present the 195Å (Fe XII) data, only, which is sensitive to material at approximately 1.6$\ 10^6$K. The images were recorded on a $1024\times1024$ pixel (44.2 $\times$ 44.2 arcmin) CCD camera with a spatial resolution of 2.59 arcsec. Each event is presented as a series of images which have been enhanced by digitally substracting the previous image (running-difference method) after exposure time normalization. The method highlights only the changes which occur in the images, with light (dark) regions indicating areas which experienced an increase (decrease) in emission. The running difference images were examined in conjunction with the standard EIT images for evidence of propagating transient brightenings. Solar rotation correction was not necessary due to the comparatively short time interval between exposures.

In assembling the catalogue, we started with a list of type II bursts. Then the EIT data corresponding with the type II burst time intervals were examined. This led us to the discovery of some additional wave effects. Afterwards,

Figure 6: Event III on 1 April 1997

basing on the list of EIT wave events we were able to find some not yet identified faint type II bursts. The EIT wave event list was compiled by examining all of the 195 Å data which were obtained at a high cadence (more than 1 image per 30 minutes). Data obtained at a lower cadence would be unlikely to show evidence of any wave transients.

Figure 7: Top - event I, bottom - event II on 2 April 1997

Figure 1 shows a strong example of an EIT wave, consisting of a brightening propagating away from the flaring region. The wave is observable in (4) consecutive images, while most of the waves in this catalogue were not observed in more than two images. In some cases, a wave is only observed in a single image. Although it is most ideal if a wave observation exhibits evidence of motion, but the low image cadence and low amplitude of the brightenings can prohibit this. In the catalogue, a wave observed in a single image is listed because it has an appearance similar to waves observed in multiple images: a diffuse brightening visible in a single location for only one image, with propagation appearing to center on a flaring region.

Figure 8: Event on 7 April 1997

Figure 9: Event on 15 April 1997

For supplementary information we used BATSE - CGRO, Yohkoh hard X-ray, and GOES soft X-ray data provided by the Solar Data Analysis Center (SDAC) at Goddard Space Flight Center.