Our Sky-Watcher HelioStar 76Ha Solar telescope mounted on the observatory’s permanent mount. The focuser, for those new to these things, is operated via the silver knob seen at the lower end of the telescope. Photo by James Guilford.
A couple of days ago, during a rather ambitious solar imaging session, the focuser on our Sky-Watcher HelioStar 76Ha telescope failed. And by failure, we mean the specialized diagonal that holds an eyepiece or camera would not stay put! The focuser would barely move the assembly and, once released, the diagonal plus camera would … zzzzzzip! … slide outward as far as it could. As one might expect, that sort of thing makes the telescope worthless. Disappointment? Disaster?
Contacting Agena Astro, the telescope’s seller, their rep. reminded us that the unit was still under warranty and supplied contact information for Sky-Watcher USA’s Support. Sending off an email describing the issue we waited a reply. “Sounds like the focuser might need to be adjusted,” came the reply a short time later. “Don’t worry we have a lot of adjustment with this focuser.” Adjusting three screws on the telescope, as instructed, and within five minutes the system was working good as new!
The Sun as it appeared via hydrogen-alpha light on April 24, 2026; as imaged using the Sky-Watcher HelioStar 76Ha Solar telescope, and a ZWO ASI monochrome camera. False color applied. Image by James Guilford.
So there was a little scare. Excellent support provided by the retailer and the manufacturer. A quick fix. And we were able to take advantage of excellent conditions today, making images of our local star! Thanks go out to Agena Astro and Sky-Watcher USA!
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.
Stella-Luna Observatory 