This has been a noticeably quiet solar maximum with the sun staying fairly calm throughout the summer, making the current activity something of a surprise, they said.
"It hadn't been active in months, so it's like it finally woke up," Holly Gilbert, a solar physicist at NASA Goddard Space Flight Center, told the Los Angeles Times. "For those of us who study the dynamics of the sun, it is exciting because it gives us more events to study."
Solar flares send radiation and solar material hurtling through space, creating space "weather" that can sometimes affect satellites and communication when it reaches Earth.
Many of the flares originated from sunspot AR1884, a particularly active region of the sun that is currently facing Earth, almost at the center of the star, Gilbert said.
A sunspot is created when magnetic fields on the sun interact and twist together.
"You get a tangled bunch of magnetic fields, and they get too tangled and too stressed, they end up erupting," Gilbert said.