Solar Observation – September 7, 2025

On September 7, 2025, I had the opportunity to observe the Sun under excellent conditions. The solar activity was remarkable, with several prominent sunspot groups visible in white light and plenty of dynamic features in H-alpha.

Solar Activity Context

September 2025 falls near the peak phase of Solar Cycle 25, which began in December 2019. The cycle reached its maximum around mid-2024, but activity remained high throughout 2025. During early September, the monthly sunspot number was still elevated, averaging around 160–170, which is significantly higher than the previous cycle’s peak (Cycle 24 peaked at about 116). This period was characterized by frequent sunspot groups, active regions, and occasional flares.

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White Light Observation

Using my TS-Optics PhotoLine 80mm refractor equipped with a Solar wedge and an 8mm Tele Vue Ethos eyepiece, I observed the Sun in visible light. The disk displayed multiple sunspot groups, some of them quite large and complex. The level of detail was impressive, showing clear umbra and penumbra structures.

I captured a photograph with my Canon EOS 80D through the PhotoLine 80mm telescope:

To complement the photo, I made a sketch of the Sun in white light, highlighting the sunspot groups and their positions:

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H-alpha Observation

Switching to H-alpha, I used my Coronado SolarMax 40 telescope with the same 8mm Tele Vue Ethos eyepiece. The view was stunning: filaments stretched across the solar disk, and several prominences were visible along the limb. Active regions showed bright plages, indicating strong magnetic activity.

Here is my H-alpha sketch, showing the filaments, prominences, and active regions:

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Summary

This session was a perfect example of why solar observing is so fascinating. In white light, the sunspots tell the story of magnetic activity on the surface, while H-alpha reveals the dynamic chromosphere with its filaments and prominences. Combining photography and sketching allowed me to capture both the scientific and artistic aspects of the observation.

Equipment used:

• White Light: TS-Optics PhotoLine 80mm, Solar wedge, 8mm Tele Vue Ethos, Canon EOS 80D
• H-alpha: Coronado SolarMax 40, 8mm Tele Vue Ethos