Coronal mass ejection associated with the stationary post-flare arch of 21–22 May 1980

Abstract

By using a combination of X-ray (HXIS), Hc~ (Haleakala), white-light corona (Solwind), and zodiacal light (Helios) images on 21-22 May, 1980 we demonstrate, and try to explain, the co-existence of a coronal mass ejection with a stationary post-flare coronal arch. The mass ejection was seen, both by S olwind and Helios, in prolongation of the path of a powerful spray, whereas the active region filament did not erupt. A tentative comparison is made with other occurrences of stationary, or quasi-stationary post-flare coronal arches.

Hard X-ray images of possible reconnection in the flare of 21 May, 1980

“…Groups of loops appear to be enhanced, or formed, at a given altitude and several minutes can elapse before a new group of loops is enhanced higher in the corona. It is important to mention that the active-region filament, though greatly activated, did not erupt upwards and never fully disappeared (McCabe et aL, 1985). Instead, a powerful surge was ejected towards the south at 21: 05:20 UT.…”

X-ray observations of filament eruption in the 1980 May 21 flare

“…McCabe et al (1986) suggest that the entire filament never erupted, but rather that part of its southern end was ejected and traveled around over-lying arches and laterally upward. He photos from Holloman Solar Observatory (Figure 1 of Rust, 1984) show strands of ejecta obscuring the He ribbons.…”

“…During the soft X-ray decline, post-flare loops were observed, crossing the neutral line, and nearly perpendicular to it -loops that are generally understood to result from reconnected field lines which have closed beneath an erupted filament. A coronal mass ejection followed (McCabe et al, 1986).…”

Relationships among flare images at different wavelengths

“…Sometimes quite a number of flare images at different wavelengths can be put together, like, for example, by McCabe et al (1986) for another famous flare, of 21 May 1980. The authors were able to compare the H~ photograph of Haleakala, showing the flare and a major spray propagating southwards, with a giant coronal arch imaged in X-rays by HXIS, two images of the radio storm above the arch, imaged at Culgoora, and a mass ejection observed by the NRL Solwind coronagraph in extension of the propagating spray (cf.…”