Two large groups of sunspots, Active Region AR2993 and AR2994, have rotated into view on the Sun. A sunspot is an area on the Sun’s visible surface that appears darker than the surrounding areas. They are darker due to a reduced surface temperature caused by a concentration of magnetic fields. Still, they sizzle at a temperature of 3,000-4,000 degree Celsius! Sunspots change shape and size over time, making them fascinating to observe.
Just a few days earlier on 17 Apr 2022, AR2994 unleashed an X-class solar flare. Solar flares are explosions of energy on the sun that send energy and particles into space. They are classified into A, B, C, M, and X classes, each 10 times more powerful than the previous. Each class is further graded on a scale of 1-9, except for X-class flares which have no upper limit on the scale. X-class flares are so powerful that they can cause geomagnetic storms that disrupt communications, damage satellites, and even damage power grids. For example, the Halloween Storms of 2003 caused a 1-hour long power-outage in Sweden.
We are now moving toward the peak of Solar Cycle 25, which is projected to be around 2025. The solar cycle is an 11-year cycle where the Sun’s activity moves from a minimum to a maximum and back again. The Sun’s activity is measured in terms of the number of observed sunspots on the sun’s surface.
I’m looking forward to more exciting solar observations in the months ahead!