Separate source, input, transform, and output
A source might be an ephemeris, catalog, map, or archival record. Inputs select a moment and viewpoint. Transformations derive geometry and styling. The output is the rendered artifact. Mixing those layers makes later verification difficult.
Keep uncertainty attached to the claim
A hospital campus coordinate reconstructed from a map is not the same kind of evidence as a ward location documented on a floor plan. Provenance should preserve that difference instead of flattening both into latitude and longitude.
Version the computational environment
Catalog releases and source datasets change. Gaia, for example, is published through named data releases, while JPL Horizons itself has documented system versions. A reproducible chart should be able to say what data and logic it used.
Sources: ESA Gaia — Data Release Scenario · NASA/JPL — Horizons System Manual
Provenance is part of the aesthetic argument
For Spatial Press, the point is not merely defensive documentation. The path from record → coordinate → sky geometry → object is part of what makes the finished artifact interesting.