A filament eruption was observed near N07W12 around 05:00 UTC on July 23. The associated coronal mass ejection (CME) was first detected in STEREO A coronagraph imagery at 05:23 UTC, with a secondary portion of the eruption becoming visible in LASCO C2 imagery around 07:48 UTC. This secondary component appeared as a very faint, partial halo.
Modeling of the event suggests the CME is Earth-directed and will likely arrive near midday UTC on July 27.
The faintness of the halo in coronagraph imagery indicates the CME is likely of low density or narrow angular width, potentially limiting geomagnetic impacts, but further observations are ongoing.
“Our Sun rapid-fire launched multiple solar storm today, but they were so close together in time that they look as if they are one structure in coronagraphs,” Space Weather Physicist Dr. Tamitha Skov said on July 23.
“The first animation shows the past 48 hours on the Earth-facing Sun. Late on July 22, you can see a slight “puff” just to the east of Region 4150. This launches the first solar storm, destabilizes the area between Region 4149 and 4150, and sets the whole chain of events in motion. Next, early on July 23, the filament near center disk launches slowly.
“This is the main Earth-directed eruption, which was already unstable, but the first eruption pushed the filament past the tipping point. Then finally, by mid-afternoon on July 23, Region 4149 finally lets go of the remaining material connected to the filament. It is a three-part process that is deceptively complex.”
Our Sun rapid-fire launched multiple #solarstorms today, but they were so close together in time that they look as if they are one structure in coronagraphs. Here is a thread that discusses the event in detail. The first animation shows the past 48 hours on the Earth-facing… pic.twitter.com/NIYjiCsYCi
— Dr. Tamitha Skov (@TamithaSkov) July 23, 2025
A detailed animation illustrates the trajectory of the Earth-directed components of this complex eruption. The dark features, highlighted by ovals, mark the regions where the final two segments of the filament tore away from the Sun.
To break things down a bit more simply, here is a detailed animation that shows the scars created by the two bits of the complex eruption that are Earth-directed. These dark scars are highlighted by the ovals and show where the final two bits tore off from the Sun. pic.twitter.com/bQHPco3KuH
— Dr. Tamitha Skov (@TamithaSkov) July 23, 2025
The eruptions occurred in such close succession that coronagraph imagery presents them as a single, coherent structure lifting off from the Sun.
However, discrepancies in the halo signature reveal a more complex event. While it initially appears as a singular eastward-directed launch, this does not align with the actual source location, west of the solar disk center.
In reality, the event produced multiple partial halos, with separate components propagating eastward, northward, and southward, Skov said.
Now, here is what makes things interesting. These eruptions happened so close together that in coronagraphs, they look like a single structure launching off of the Sun. But the clue that something is wrong comes from the halo signature itself. At first glance, it looks like a… pic.twitter.com/6W30YtkTju
— Dr. Tamitha Skov (@TamithaSkov) July 23, 2025