BERLIN — Parts of Britain and Germany have been treated to a display of the northern lights, a colorful phenomenon that is usually only seen farther north.

The aurora borealis painted skies green, purple, and blue late Sunday and early Monday as far south as the southern English county of Oxfordshire, as well as in some northeastern regions of Germany.

An aurora appears when a magnetic solar wind — made up of electrically charged particles from the sun — slams into the Earth’s magnetic field, exciting electrons of oxygen and nitrogen.

Amanda Townsend, a space weather adviser for Britain’s Met Office, said that ‘‘once in a while the solar winds are enhanced to levels stronger than normal, with particles at higher speeds.’’ She added that ‘‘on this occasion it has connected really well with the Earth’s magnetic field.’’

An intense solar wind was caused by a particularly large and fast eruption on the sun’s surface Feb. 25, allowing the aurora to be seen farther south than usual. They were also spotted in New England.

Sky-watchers took to social media to share photos.

As solar winds distort the Earth’s magnetic field, some charged particles from the sun are able to enter the Earth’s atmosphere at the magnetic north pole and the magnetic south pole. The charged particles then excite gaseous oxygen and nitrogen in the atmosphere, making them glow.

Associated Press