Sun Erupts With 4th X-class Solar Flare This Week

After not producing any X-class eruptions all year, the Sun has roared to life this week, producing its fourth X-class solar flare of the week on Tuesday.

Tuesday's flare came from the same region as the previous X-class flares this week, an active sunspot region known as AR1748. Prior to this week the sunspot region did not even have a name and was difficult to see, but as the region continues to rotate towards Earth, scientists will be able to observe it more clearly.

Registering at X1.2, Tuesday's flare was the weakest of this week's X-class flares, which are the most powerful type of flares that the Sun can unleash. Monday night's X3.2 flare was the strongest of the year. The numbers the flares are assigned correlate to their strength. An X2 is twice as intense as an X1; an X3 is three times as intense, and so on.

It is still unknown whether a coronal mass ejection (CME) resulted from Tuesday's flare, though the event did produce a radio blackout, the Space Weather Prediction Center reported. The week's earlier X-class flares did result in CMEs, including one unusually fast one, but none were Earth-directed.

The space weather center said that if a CME did occur from Tuesday's flare it "may just glance the Earth's magnetic field."

When strong CMEs reach Earth they have the power to blowout transformers in power grids and disrupt radio communications as well as enhance northern lights displays.

Increased numbers of solar flares are expected as the Sun enters the peak of high activity in its 11-year cycle, known as the solar maximum. The Space Weather Prediction Center reported upcoming solar activity to be moderate with a 50 percent probability of more X-class flares erupting between now and May 17.

The strongest flare recorded during this Sun cycle was an X6.9 on Aug. 9, 2011. So far, there have been 19 X-class solar flares in Solar Cycle 24, which begain January 2008.