# SUN – Mercury transit mosaic in Hydrogen Alpha

Mercury crossing the solar disc, assembled from several frames, in hydrogen alpha, the red line of hydrogen at 656.28 nm. The planet is a small black circle, sharper edged and far darker than any sunspot. The DayStar Quark passes half an angstrom or less of that line, narrow enough to show the chromosphere, the layer above the visible surface, instead of the surface itself. Photographed with a Skywatcher Esprit 100 at 550mm on an ASI174MM-COOL.

- **Category:** Solar
- **Equipment:** Skywatcher HEQ5 – Skywatcher Esprit 100 F/5.5 Triplet Super APO (550mm) – Daystar Quark Chromosphere HA – ASI174MM-COOL
- **Published:** 2026-08-21
- **Photographed:** 2026-08-21

![SUN – Mercury transit mosaic in Hydrogen Alpha](https://astro.observer/images/sun-mercury-transit-mosaic-in-hydrogen-alpha/sun-mercury-transit-mosaic-in-hydrogen-alpha-3200.jpg?v=4f2caf7166)

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