AWhat changed
A photographic system distinguishes ellipticals, normal/barred spirals and irregular forms, supplying reproducible categories for comparing populations.
Scientific scope
A photographic system distinguishes ellipticals, normal/barred spirals and irregular forms, supplying reproducible categories for comparing populations. This is a descriptive classification of projected images. Early and late type names do not establish an evolutionary sequence. The paper's historical luminosity and distance assumptions are not adopted here.
Evidence
Source-linked, scoped account of the original work. The published scope states the scientific assumptions and remaining verification limits. WRS has not independently certified the full proof, experimental result or system benchmark.
Contributors
- Edwin Hubble · SCIENCE: Original source-listed scientific author of this scoped work; byline does not determine effort fractions.
Provisional WRS assessment, edition 2026-10-16.1. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
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