24 Nov 2025
Combined datasets of T-17 and SPA-2 of M81 Presented in HaLRGB format. Processed in Astro Pixel Processor, Pixinsight, and Photoshop. I wanted to get as much fine detail as possible without over-sharpening, so lots of masking and processes were used. Messier 81 is located in Ursa major, which is the same constellation where the big dipper is, 11.8 million light years distant. It has a relatively high surface brightness, making it easily visible to small telescopes.
M81
20 credit
Filtro | Exp. media (s) | Esposizione totale | Sottoframe |
|---|---|---|---|
| Luminance | 1705 | 9h | 19 |
| Red | 758 | 4h | 19 |
| Green | 758 | 4h | 19 |
| Blue | 800 | 4h | 18 |
| Halpha | 1800 | 9h | 18 |