The biggest sunspot in nearly 25 years is about to leave the solar disk. The series of flares over the course of the previous week all erupted from a particularly large active region on the sun, labelled AR 12192 – the largest sunspot group seen on the sun in 24 years.
Continuing a week’s worth of substantial flares (seven X-class flares in 9 days) beginning on Oct.19, 2014, the sun emitted two mid-level solar flares on Oct. 26 and Oct. 27. The first flare was classified as an M7.1-class flare. The second flare was a bit weaker, classified as an M6.7-class. The most intense of these flares have caused HF radio blackouts and other communication disturbances on the day-side of Earth.
Usually, strong flares are accompanied by massive CMEs. So far, however, none of the eruptions from AR2192 has produced a major CME. Without a series of CMEs to hit Earth and rattle our planet’s magnetic field, there have been no geomagnetic storms nor any widespread auroras. AR2192 will soon rotate over the western side of the Sun and will no longer be facing Earth.
In only a few days, the behemoth sunspot will begin a 2-week transit of the far side of the sun, carried around by the sun’s 27-day rotation. However, that doesn’t mean we’ve seen the last of this magnificent active region. Big sunspots typically persist for two or three solar rotations before they decay. After it leaves, AR2192 will return in November.
Bellow it follows a synoptic chart of the X-ray flux daily maximum and the sunspot’s group 2192 size. The time interval was selected to be fro the sunspot’s group first appearance in eastern limb at Oct. 18 to its departure from the visible solar disk at Oct. 28.