Credit: Sky-Watcher
Key Takeaways:
- The Sky-Watcher Heliostar 76mm H-Alpha Solar Telescope is introduced as an accessible instrument for amateur solar observation, featuring a 76mm f/8.3 objective and an integrated high-performance single-stack Solis etalon.
- This telescope employs a specialized etalon to isolate the Hα wavelength (656.28 nm) with a bandpass of less than 0.5 Ångstroms, utilizing a Trifid pressure tuner to maintain performance across temperatures and achieve high clarity comparable to dual-etalon systems without light loss.
- The instrument incorporates essential features for precise and safe solar viewing, including a dual-speed Crayford focuser, a 90° diagonal with an ISO 12312-2 compliant blocking filter, a permanently mounted solar finder, and various accessories for enhanced user experience.
- Performance evaluation indicated that the Heliostar 76 provides remarkably sharp and clear views of dynamic solar features such as sunspots, filaments, and prominences, demonstrating superior image quality compared to a smaller aperture single-stack Hα telescope.
Although I’ve spent decades as a deep-sky observer, I’ve always been fascinated by the Sun. Solar observing offers clear advantages: It’s accessible anywhere, immune to light pollution, and doesn’t require staying up late. Best of all, the Sun is dynamic. The view changes daily.
While white-light filters are great for showing evolving sunspots, most of the action is only visible through telescopes equipped with specially designed Hydrogen-alpha (Hα) filters. Through these, it’s an entirely different star. An Hα filter reveals the chromosphere, the dynamic layer just above the Sun’s visible surface, the photosphere. The first time I looked through one decades ago, I was stunned by the view of prominences, plages, and filaments strewn across the solar disk. I just had to get one.
Back then, such instruments were rare and costly, found mainly in large observatories. But times have changed. Today, more affordable Hα telescopes are widely available, including a remarkable model introduced in 2024 by Sky-Watcher Instruments.
What’s inside
The Sky-Watcher Heliostar 76mm H-Alpha Solar Telescope brings Hα observing into the reach of amateur astronomers. The core of the instrument is a finely crafted 3-inch (76 mm) f/8.3 fully multicoated doublet objective.
A defining feature that sets the Heliostar apart from other amateur Hα solar telescopes is its integration of a high-performance single-stack Solis etalon. An etalon is a special optical device used in solar telescopes to isolate the red Hαwavelength (656.28 nanometers). It comprises two extremely flat, highly reflective glass plates positioned close together and kept precisely parallel. When light enters the etalon, it bounces back and forth between these surfaces. Because of the way light waves interact, a process called interference, the etalon blocks out most sunlight and allows only a narrow range of wavelengths around the Hα wavelength to pass through.
Some observers use setups with two etalons to further isolate Hα light, improving clarity and contrast. However, such systems can result in faint images through an eyepiece (remember, we’re isolating a tiny fraction of the Sun’s light).
The Heliostar stands out by using a single high-finesse Solis etalon (“finesse” meaning how precisely it isolates wavelengths), achieving a bandwidth of less than 0.5 Ångstroms. Such a narrow window assures sharp detail. Its Trifid pressure tuner maintains performance across temperatures, avoiding the problems faced by some Hα systems. The Heliostar also preserves brightness while delivering clarity and contrast comparable to dual-etalon systems, but without the light loss.
The Heliostar comes with a sturdy dual-speed 2-inch Crayford focuser that makes precise adjustments easy. Fine focus is crucial when viewing narrowband solar features, where even slight deviations can soften the image.
The 90° diagonal included with the Heliostar is not your ordinary star diagonal. Inside, a permanently mounted blocking filter that meets ISO 12312-2 solar safety standards further blocks non-Hα wavelengths. The filter ensures that the final image reaching the eyepiece is both bright and safe.
The telescope tube has a matte white finish that helps reduce heat buildup in sunlight. The tube rings and Vixen-style mounting plate are finished in bold green anodizing. Together, these colors give the Heliostar a striking appearance that’s sure to attract attention.
Sky-Watcher also includes several useful accessories, among them a clip-on sunshade. This item attaches to the tube and blocks sunlight from entering the observer’s eye during use. The shield makes viewing our star on a sunny day much more comfortable.
Sky-Watcher permanently mounted a small solar finder on one of the tube rings. This device allows for safe and easy solar alignment by projecting a small image of the Sun onto a built-in screen. When the Sun’s dot is centered on the screen, the telescope is aimed.
Other accessories include a 20mm wide-angle eyepiece, which offers a 70° apparent field of view. It’s a good start for general solar viewing, but owners can use any 1¼” eyepiece. There’s also a smartphone adapter for those interested in trying basic imaging. Everything fits securely in a rugged, foam-fitted case.
For this review, Sky-Watcher also supplied its SolarQuest mount, designed specifically for solar observing. (The mount can be purchased together with the telescope as a kit.) It uses GPS and a HelioFind sensor to automatically orient, locate, and track the Sun. Setup is simple: Place it on a tripod, turn it on, and it self-aligns and starts tracking the Sun within minutes. You’ll find a review of this mount in the September 2023 issue.
Setup and use
The Heliostar telescope arrived assembled, double-boxed, and securely packed in a foam-lined carrying case. The SolarQuest mount and tripod came the same day in a separate, well-padded box.
Assembly was straightforward. I extended the tripod legs, attached the accessory tray, and placed the extension pier on top. After threading the SolarQuest mount onto the pier, I adjusted the tripod until the mount’s bubble level showed it was leveled.
Once the mount was assembled, I attached the Heliostar in its sidesaddle configuration. I oriented the dovetail groove, seated the mounting plate, and tightened the knob securely. After powering on, the mount acquired a GPS signal and slewed automatically to the Sun, confirming alignment with a steady red LED.
After I inserted the supplied 20mm eyepiece into the diagonal and adjusted the focus, the Sun’s surface snapped into stunning detail after a slight tweaking of the pressure tuner. Through the eyepiece, I observed intricate sunspot groups, fine granulation, sinuous filaments, and delicate prominences along the Sun’s limb. The image was remarkably sharp and clear, revealing far more than I expected at this aperture.
For comparison, I also set up my own “Brand X” single-stack Hα solar telescope next to the Heliostar. Swapping the 20mm eyepiece back and forth, I found the Heliostar’s view was far sharper and higher in contrast. Admittedly, the Heliostar had a larger aperture (76mm versus 60mm), but the difference in image quality left a strong impression.
Credit: Tony Carro
Photography
Imaging the Sun with the Heliostar 76 ranges from basic to advanced. The included smartphone adapter allows for simple photos of prominences and filaments, though image quality is limited.
A DSLR or mirrorless camera at prime focus offers better resolution, but managing exposure can be difficult. Images can still appear overexposed, even with the camera set to its lowest ISO and fastest shutter speed.
To achieve those sharp, high-contrast solar images seen online, a monochrome astronomy camera, high-speed video capture, and image-stacking software such as AutoStakkert! or RegiStax are essential. With the right setup, the Heliostar can deliver remarkably detailed views of the active photosphere.
Conclusion
I absolutely loved using the Heliostar 76 paired with the SolarQuest mount. Together, they form a complete, brilliantly designed solar observing system that’s ready to go right out of the box.
Whether for visual exploration or solar imaging, this setup delivers crisp, detailed views that left me genuinely impressed. And the fact that it outperforms many pricier double-stack systems makes it a compelling value for dedicated solar observers.
PRODUCT INFORMATION
Sky-Watcher Heliostar 76
Aperture: 76 millimeters
Lens: Achromatic doublet
Focal ratio: f/8.3
Focal length: 630 millimeters
Bandpass: Less than 0.5 Ångstroms
Length: 24 inches (61 cm)
Weight: 8.4 pounds (3.8 kg)
Also included: mounting rings, 20mm eyepiece, diagonal, sunshade, solar finder, cellphone adapter, case
Price: $3,395 (telescope only) / $3,895.00 (with SolarQuest mount)
Contact: Sky-Watcher
2835 Columbia Street
Torrance, CA 90503
1-855-327-1587 x306
www.skywatcherusa.com
