# Sun (AR 4197) in H-alpha and Calcium-K

Active region AR 4197 photographed in two lines side by side. Hydrogen alpha at 656.28 nm, the orange panels, shows the chromosphere: its fibril texture, bright plage around the spots and a prominence off the limb. Calcium K at 393.4 nm, the violet panels, reaches a different height, roughly 500 to 2000 km above the surface, and renders the same region as dark cores in a mottled bright field. Photographed with an Svbony 432MC through a DayStar Quark hydrogen alpha filter and an Antlia 3nm calcium K filter.

- **Category:** Solar
- **Equipment:** Skywatcher GTI · Svbony 432MC · Daystar Quark Hydrogen Alpha · Antlia CaK 3nm · AstroDMX with Kstars/Indi · Pixinsight – Photoshop
- **Published:** 2025-09-03
- **Photographed:** 2025-09-03

![Sun (AR 4197) in H-alpha and Calcium-K](https://astro.observer/images/sun-ar-4197-in-h-alpha-and-calcium-k/sun-ar-4197-in-h-alpha-and-calcium-k-3200.jpg?v=f4c9029bff)

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