A multi-wavelength analysis of the February 6/7. 1997 coronal mass ejection

S. P. Plunkett, N. Gopalswamy, M. R. Kundu, R. A. Howard, B. J. Thompson, J. B. Gurman, R. P. Lepping, H. S. Hudson, N. Nitta, Y. Hanaoka, T. Kosugi, and J. T. Burkepile

E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, D.C.


The partially earth-directed coronal mass ejection (CME) event of February 6-7, 1997 originated from the southwest quadrant of the sun. The CME accelerated from a projected speed of 170 km/s to about 650 km/s when it reached a distance of 25 RE. The CME was an arcade eruption followed by bright prominence core structures. The prominence core was tracked continuously from the solar surface to the interplanetary medium by combining data from the Nobeyama radioheliograph (microwaves), Mauna Loa Solar Observatory (He I 10830 D ), SOHO/EIT (EUV) and SOHO/LASCO (white light). The CME was accompanied by an arcade formation, fully observed by the Yohkoh/SXT (soft X-rays) and SOHO/EIT. The X-ray and EUV observations suggest that the reconnection proceeded from the northwest end to the southeast end of a filament channel. In the SOHO/EIT images, the feet of the soft X-ray arcade were observed as EUV ribbons. The CME event also caused interplanetary effects that were observed by instruments on WIND, and produced a medium sized geomagnetic storm at Earth starting on February 9. This event confirms a number of ideas about CMEs: the three part structure (frontal bright arcade, dark cavity and prominence core), disappearing filament, elongated arcade formation , and terrestrial effects. We make use of the excellent data coverage to address a number of issues regarding the origin and propagation of geoeffective solar disturbances.

Proceedings of the Fifth SOHO Workshop, ESA SP-404, 615, 1997