The Sharpless Catalog Builder is a free desktop app for planning and logging sessions across the 313 emission nebulae of the Sharpless (Sh2) catalog — the deep end of the narrowband target list, for when you've worked through Messier and Caldwell and want more. The survey it's drawn from covers the northern sky, so the catalog is well within reach for astrophotographers across North America and Europe.
It lays out all 313 objects as one chart, with your own captures dropping into their tile as you shoot them, and a running total in the corner so you can watch your progress across a genuinely large catalog.
For each object you can log your exposure time, sub-length and count, gain, and the equipment you used, along with your own notes, building a complete record across a catalog that's largely faint, narrowband territory.
Like its companions, it's a native desktop application that runs entirely offline on your own machine — nothing is uploaded, and your logs stay on your computer. Available for Windows and macOS (both Apple Silicon and Intel). It's the companion to the Messier and Caldwell Catalog Builders, using the same session-logging workflow so your records stay consistent across all three catalogs.
