Barnard Catalog Builder
A free, offline desktop app for planning, imaging and logging E. E. Barnard's dark nebulae - from the Horsehead and the Snake to the Pipe and Barnard's E. A companion to the Messier, Caldwell and Sharpless builders.
Download free Browse all toolsEdward Emerson Barnard photographed the Milky Way's dark clouds in the early 1900s and catalogued them as "dark markings of the sky." His 1927 catalogue numbers them B1 to B175 and B201 to B370 - 345 objects, as the numbers 176-200 were never used.
The builder lays out every Barnard object on one chart, with the famous ones named on their squares. Drag your photos onto the window and each one lands in the right square: name your files B33.jpg or Barnard 72.png, or use a well-known name such as Horsehead or Pipe.
Right-click a photo to adjust its framing, rest your mouse on it for a 300 × 300 preview, switch the twinkling star border on or off, and export the finished chart as PNG, JPG or TIFF. Everything stays on your computer, and it runs on Windows and on both Apple Silicon and Intel Macs.
Frequently asked questions
What's new in version 1.3?
Right-click a photo to adjust its framing (move and zoom the crop, or show the whole photo). File names can now use object names as well as numbers. 16-bit and 32-bit TIFFs from Siril, PixInsight and other stacking software work, and unstretched (linear) stacks are brightened automatically. There's also Undo for removed or replaced photos, a progress bar for big batches, a Missing list you can save as a checklist, and a short welcome guide the first time the app opens.
Is it really free?
Yes. No account, no subscription and no ads. Download it and start.
Does it need the internet?
No. It runs entirely on your computer. Your photos, chart and logs never leave it - the app works from copies and never changes your original files.
Windows says "Windows protected your PC" - is it safe?
That warning appears for any app that isn't from the Microsoft Store. Click More info, then Run anyway. Some antivirus programs flag apps packaged this way by mistake; if yours removes it, restore it from its quarantine and allow it.
My Mac says it "cannot verify" the app.
The app isn't from the App Store, so macOS asks once. Click Done, open System Settings → Privacy & Security, scroll down and click Open Anyway. Pick the Apple Silicon download for M1-M4 Macs and the Intel download for older Macs.
What can I log for each object?
Right-click a photo and choose Add log / notes: dates, total exposure, sub length and count, gain or ISO, telescope or lens, camera, mount, filters, other equipment and your own notes. Each log is saved as a text file next to the photo, and a summary shows when you hover over it.
Why does the chart jump from B175 to B201?
Barnard never used the numbers 176 to 200 in his 1927 catalogue, so there is nothing to photograph there. The chart follows his numbering, so B201 comes right after B175.
How do photos get matched to squares?
Name the file with its Barnard number - B33.jpg, Barnard 72.tif - and it goes straight to the right square. Horsehead, Snake, Ink Spot, Parrot's Head, Seahorse, Pipe and Barnard's E also work by name. Anything else, drop it on the square you want.
Ready to start logging sessions?
Free, offline, and your data stays on your computer.
Version 1.3 · Updated November 2026