SkyWatcher Heliostar-100Hα 100 mm H-Alpha Solar Telescope

The SkyWatcher Heliostar-100Hα is a specialised solar telescope designed for observing the Sun in H-alpha light. Unlike white-light viewing, H-alpha reveals features in the solar chromosphere, including prominences at the solar limb, filaments, active regions and flares. It is intended for solar observing and imaging, not as an all-purpose telescope for night-sky or deep-sky use.

The 100 mm optics have a 760 mm focal length at f/7.6. The integrated Solis etalon system provides a very narrow bandpass below 0.5 Å according to the manufacturer, with wavelength tuning by pressure tuning. With the supplied 22 mm wide-angle eyepiece, the manufacturer specifies 36.4x magnification. The built-in solar finder helps align the telescope with the Sun without looking directly toward it through the telescope. A 2-inch dual-speed Crayford focuser provides focusing control.

Important safety information: The 20 mm blocking filter in the removable solar diagonal is part of the safety system. Never use the telescope with a different diagonal or without this blocking filter. Point and operate the instrument only as described in the supplied manual, and do not alter or remove filter components. The manufacturer states that the product meets the transmission requirements of ISO 12312-2:2015. This statement does not replace safe operation according to the manual.

The set includes the Heliostar telescope, a 90-degree solar diagonal with 20 mm blocking filter, built-in solar finder, 22 mm eyepiece, tube rings, 45 mm dovetail bar and aluminium case. For CCD use, the manufacturer specifies a 1.25-inch adapter and 60 mm back focus; visual back focus is 20 mm. This is an optical tube with accessories, not a GoTo mount or a general-purpose refractor set with tripod.

Specifications and features

Included in the set

• Heliostar-100Hα optical tube
• 90-degree 1.25-inch solar diagonal with integrated 20 mm blocking filter
• Built-in solar finder
• 22 mm eyepiece
• Tube rings with integrated handle
• 45 mm dovetail bar with 1/4-inch photo thread
• Aluminium carrying case