Sharpless H II Regions: Catalog of Ionized Hydrogen Nebulae

A database table derived from the Sharpless Catalogue of H II regions, originally published in 1959. The data is provided by NASA HEASARC and includes quantities not present in the original published catalog. The equatorial coordinates have been precessed, with their epochs determined empirically from the original computer card data.

Use Cases

• Identify and catalog H II regions based on the Sharpless classification.
• Study the spatial distribution of ionized hydrogen nebulae using the precessed equatorial coordinates.
• Analyze historical astronomical data from the 1959 catalog for comparative studies.

Strengths

• Derived from a seminal 1959 catalog published in the Astrophysical Journal Supplement Series.
• Includes quantities not present in the originally published catalog.
• Provided by the authoritative NASA HEASARC service.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Original data is from 1959, potentially lacking modern observations.

Provenance

Source

NASA HEASARC

Collection Method

Converted from original 026 and 029 punch card decks of the Sharpless Catalogue.

Time Range

Catalog originally published in 1959.

Freshness

Last updated 2026-03-13 19:52:17.133119; freshness should be verified.

Geography

Celestial coordinates; spatial coverage is the observable sky.