Last imaging for a while

This image depicts the northeast quadrant of our Sun, as recorded the morning of March 2, 2026. The data collected were in hydrogen-alpha light and depict well the turbulent curves in the chromosphere resulting from Solar plasma interacting with strong magnetic fields surrounding two sunspots shown here, left to right: Active Regions 4384 and 4381. Several tenuous prominences are found along the rim of the circle. This is a non-colored monochrome image. // James Guilford, Stella-Luna Observatory

It was the last sunny day expected for, likely, a week so we had to get out and image our Sun. Well, we would have done it anyway! Seeing conditions were forecast to be better than average but at midday, when we have our first clear shot at Sun, the atmosphere was stirred up and shaking our view. Still, the miracle of “lucky imaging” came through and we were able to make passable pictures from the image data. Interestingly, the sunspots at Active Regions 4384 and 4381 are the remnants of the giant sunspot formerly known as AR4366 surviving a trip around the far side of our star! Sunspots, by the way, receive new designations when they are first observed appearing over the eastern horizon even if they were previously observed as they disappeared over the western edge.

Both of these images were the result of data stacked in ASI’s VideoStack application. The image above was then processed only in Pixelmator Pro. The image below was processed in PixInsight/Solar Toolbox, and Pixelmator Pro.

An image of our Sun taken in hydrogen-alpha light reveals a turbulent chromosphere, marked with a few dark filaments. Three sunspots are found in the left-hand portion of the disk though difficult to see via hydrogen-alpha. False color has been added to this image. // James Guilford, Stella-Luna Observatory

We captured a filaprom!

Shown in white light is our Sun as it appeared on February 4, 2026. A large sunspot, designated Active Region 4366, drew much attention as it transited the surface, issuing flares along the way.

On sunny days, this winter, when it’s not bone-shatteringly cold, we’ve been imaging Sun. In white light, we’ve tracked the progress of a couple of impressively-large sunspots as they traversed the Solar photosphere, including one designated Active Region 4366 that drew global attention in late January and early February 2026. We’ve also been observing in hydrogen-alpha (Ha) light.

The NOAA SWPC Solar Synoptic Analysis map showing Sun on February 16, 2026.

On sunny February 16, we checked the NOAA Space Weather Prediction Center’s daily Synoptic Analysis map for targets of interest. Yes! The map indicated several prominences around Sun’s rim so, a great day to see what was out there.

The full-disk image of Sun as it appeared in hydrogen-alpha light. This is a monochrome image original with false color applied. The “filaprom” is located at about the four o’clock position on the disk.

While an arch-shaped prominence at about the two o’clock position was our original target, as soon as we looked through the telescope’s eyepiece we saw it — a filaprom! What’s that? The snake-like features that appear in Ha are called filaments. If a filament bridges the Solar limb, its true nature is revealed: it’s a prominence, appearing as a dark filament when viewed against the bright chromosphere, and as a bright prominence when contrasted against the blackness of space — a filaprom! It was a first for us and delightful to observe!

Close-up view of the filaprom, near the top of the arc. Lower on the curve is a prominence issued from a position just over the Solar limb. Near the left-hand portion of the frame is a filament feature — a prominence viewed against the bright Solar chromosphere.

Improvements in instrumentation and processing skills helped with both the capture and depiction of our nearest star’s activities. We recently upgraded to the relatively-new Sky-Watcher Heliostar 76Ha telescope and that has made a huge difference in visualizing the chromosphere. The telescope’s filtering system, with a “single-stack” arrangement, is capable of 0.5 Angstrom or better which really brings out detail — stronger image “signal” produces image data that are easier to process and edit. More about the telescope another time.

The Sky-Watcher Heliostar 76Ha telescope in its parked position beneath the observatory dome.

A little extra … domy

The gray observatory is surrounded by accumulated and drifting snow. The dome itself wears an extra dome of accumulated snow.

Recent arctic-air frigid weather has brought real winter weather to our region for the first time in a few seasons. Snowfall over the past 48 hours amounted to 10 or 12 inches of light, flaky, fluff. Nighttime below-zero low temperatures have erased any thought of going out; skies have been cloudy, anyway, preventing guilt and regret. So the dome remains sealed though pointed to the south for midday solar observations. If we ever see Sun again.