On Nov 3rd 2023, several Coronal Mass Ejections (CME) hurled from the Sun towards the Earth (article from Spaceweather.com).
It means that the sun ejected billions of tons of coronal material.
According to National Oceanic and Atmospheric Administration (NOAA) website, CMEs travel outward from the Sun at speeds ranging from slower than 250 kilometers per second (km/s) to as fast as near 3000 km/s. The fastest Earth-directed CMEs can reach our planet in as little as 15-18 hours. Slower CMEs can take several days to arrive.

A full halo CME was expected to hit Earth's magnetic field on Nov. 5th 2023. A strong G2-class geomagnetic storm was annonced with auroras in northern Europe.

The weather was not good but we decided to try our chance. 100% of winners tried their luck.
But where to observe? After consulting the weather maps, we decided to go to a place where there was the highest probability of clear skies. It was not the best place for light pollution in the north, but it was better to have some lights and no clouds.

A few minutes after putting down our cameras, auroras appeared on the screens! Bingo! Auroras have spread as far as France. But with the naked eyes, we didn't see. This might have been visible without the light pollution from cities.
Red auroras come from atomic oxygen in Earth's upper atmosphee shining at 630nm. The human eye is famously insensitive to this wavelength. It takes a strong geomagnetic storm to make the red glow visible to the unaided eye.

In this image, you can see the aurora (the red "curtains"), the Big dipper on the left, Polaris and the Ursa minor, Capella and Auriga on the right over the clouds, Perseus on the top right. The city lights are those in the south of the Nancy metropolitan area.
This display lasted about 15 minutes.

Technical data: Sony A7S Astrodon on a simple tripod, Samyang 14mm f2.8, 1s, 6400 ISO. Processed with DxO PhotoLab.

According to Spaceweather.com, 2 CMEs sparked a strong G3-class geomagnetic storm with auroras as far south as Texas and Arizona.