The Sun on September 10, 2024, in H-alpha Description: Using an H-alpha (or Hydrogen-alpha) filter allows us to see solar activity in much more detail than in natural light. Dark spots are slightly cooler regions on the surface of the sun and are the starting point...
Solar Prominences on July 12, 2025 Description: A huge solar prominence was visible using a hydrogen-alpha filter on July 12. Its height was about ten times the diameter of Earth. Equipment: William Optics GT81 refractor, Daystar Quark Gemini H-alpha filter...
