Solar flare behind the west limb still registered M4.1 xray flux and launched a spectacular CME, likely headed away from Earth.
Many Earths worth of material ejected a high speed from what was easily a large X flare the visible prominence of which still registered M4.1 despite being mostly behind the the west limb of the Sun and technically out of view.
For your viewing pleasure. If you go to https://www.solarham.net/index.htm be sure and watch the SUVI 304 angstrom movies. When you really want power, the Sun delivers.