Astrophotographer Mark Johnston has produced a breathtaking video capturing the intricate movements of hydrogen plasma above the sun’s surface. The imagery showcases a delicate cloud of plasma twisting and floating in place, held aloft by powerful magnetic forces.
A Close-Up View of Solar Activity
The captivating footage, recorded on October 20, 2025, from Willow Springs Lake in Arizona, condenses 75 minutes of real-time solar activity into a mesmerizing 6.5-second looped animation. This technique allows viewers to appreciate the complex and subtle movements that unfold over a longer period. Johnston credits a recent upgrade to his solar etalon filter, which allows for exceptional results when viewing conditions are favorable.
What is a Solar Prominence?
The video focuses on a solar prominence, a large, bright structure extending from the sun’s surface. It’s also known as a solar filament when viewed against the bright face of the sun. These prominences are composed of plasma – a superheated gas made up of charged hydrogen and helium. This plasma travels along tangled magnetic field lines, which are generated by the sun’s internal dynamo (a process similar to Earth’s magnetic field generation).
Why this matters: Solar prominences are a key indicator of the sun’s activity. They can provide crucial data for understanding the dynamic behavior of our star and its influence on Earth’s space environment.
The Physics Behind the Display
The structures form when plasma becomes trapped within these magnetic field lines, effectively suspending it above the sun’s surface. Prominences can last for varying lengths of time – from a single day to several months. They can extend hundreds of thousands of miles into space, forming vast, looping shapes. Eventually, these magnetic structures can become unstable, leading to eruptions that send plasma hurtling out into space—a phenomenon that can impact our planet.
What makes this so visually striking? The red glow of the plasma is a direct consequence of the incredibly high temperatures involved.
Tools of the Trade
To achieve this remarkable level of detail, Johnston utilized a sophisticated setup:
- TEC160FL refractor: A specialized telescope designed for solar observation.
- Baader Energy Rejection Filter: Reduces unwanted wavelengths of light, improving contrast.
- Baader 4ZS telecentric: Minimizes distortion and aberrations.
- Solar Spectrum 0.3Å hydrogen-alpha etalon & Lunt hydrogen-alpha etalon: Filters that isolate the specific wavelength of hydrogen-alpha light, revealing the prominence’s details.
- ASI174M camera: A high-resolution camera optimized for astrophotography.
The use of specialized filters and a powerful telescope allowed Johnston to isolate and capture the subtle movements of the plasma within the sun’s complex magnetic environment.
The result is an unparalleled view of the sun’s dynamic behavior—a stunning reminder of the power and beauty of our nearest star. The timelapse beautifully illustrates how seemingly static structures are actually filled with ongoing movement and interconnected forces.
