Uncertainty & Provenance Policy
In observational astronomy, a number without an uncertainty interval and method tag is incomplete. A trigonometric parallax for a nearby dwarf star may be known to 0.02%, whereas the distance to a red supergiant or planetary nebula may carry 15–25% systematic uncertainty.
Structured Uncertainty Representations
FastAstro's data schema enforces typed uncertainty structures on every quantitative measurement:
- Symmetric 1σ Interval (
± value): Standard Gaussian uncertainty reported by astrometric, spectroscopic, or photometric fits. - Asymmetric Interval (
+plus / −minus): Used when nonlinear transformations (such as inverting a noisy parallax or fitting posterior orbital inclinations) produce skewed confidence intervals. - Observational Range (
min to max): Used for intrinsic physical variation—such as pulsating variable star magnitude swings, synodic planetary distance ranges, or core-to-halo angular diameters. - Exact / Defined Convention: Reserved strictly for defined IAU constants or exact spherical boundary integrations (such as IAU constellation solid-angle areas).
Handling Competing Literature Values
When independent astronomical methods yield discrepant values—for example, radio VLBI maser parallaxes versus optical Gaia parallaxes in dusty star-forming regions, or bright-star saturation in Betelgeuse and Antares—FastAstro flags the measurement status as contested or model-dependent and includes a dedicated Uncertainty & Competing Measurements section explaining the physical reason for the disagreement.