Departing Sunspots

Afternoon Session

My last solar imaging session was months ago in October!  Thereafter, most days were cloudy, or too cold, or too windy. Finally, on February 18th, a clear day arrived without strong wind or freezing temperature. I waited for afternoon to let temperature rise into the mid-40's and began imaging at 1:45 pm EST. Seeing was mediocre. There were no dramatic prominences, and most sunspots were located in the Sun's western hemisphere where they were destined to depart in the next few days by rotating out of view. The first image below is a 12-panel mosaic showing features in the western hemisphere.

Four sunspots are visible above. The most prominent one is sunspot 3226 in the northwest quadrant. In the southwest quadrant, from left to right, are sunspots 3220, 3217, and 3225. A few dark filaments appear on the disc.

Major sunspot 3226 with a light bridge across the umbra shows up well in the next close image. View it at 100 percent to see all the detail present.

Sunspots 3220, 3217, and 3225 also look nicely detailed when viewed at 100 percent in the following image of the southwest quadrant.

Sunspot 3217 is accompanied by a fan-shaped filament. Sunspot 3225 is closest to the limb where its neighboring white energetic region will rotate out of sight before the following umbra. Sunspot 3220, on the left, has a single umbra.

One other sunspot of note, 3229, was in the eastern hemisphere. It had emitted a powerful X-class solar flare just a day or two before. On February 18th, however, it appeared like this:

Evidence of 3229's eruptive nature remains in the image above. A dark filament arches above a white active area to the left of the umbra. Shooting straight up are narrow spiky eruptions emerging from the left-most white energetic area. View the image at 100 percent to see this best.

These images turned out remarkably well in spite of sometimes unsteady afternoon seeing. All images were made by stacking the best 400 frames from 4,000-frame videos.