The sun emitted two mid-level solar flares on Sept. 7, 2017. The first peaked at 6:15 a.m. EDT. The second, larger flare, peaked at 10:36 a.m. EDT. These are the fourth and fifth sizable flares from the same active region since Sept. 4.
The first flare is classified as an M7.3 flare. The second as X1.3. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc. M-class flares are a tenth the size of X-class flares.
To see how this event may affect Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov.
Explore further: Two significant solar flares imaged by NASA's SDO