Henry Draper Extension Charts: 86,933 Stars with Spectral Types and Positions

86,933 stars with spectral classifications, accurate positions, and proper motions, revived from historical chart data. The catalog is an extension of the Henry Draper Catalog, created by astronomers at the Harvard College Observatory and later digitized by Nesterov et al. in the 1990s. It was made available by NASA HEASARC in 1998.

Use Cases

• Training models for stellar spectral classification based on the catalog's original spectral types.
• Analyzing stellar proper motion patterns based on the 5.5 mas/year accuracy measurements.
• Cross-matching historical star catalogs with modern astrometric surveys using the 0.5 arcsecond accurate positions.
• Studying the distribution of fainter magnitude stars based on the HDEC's extension of the original Henry Draper Catalog.

Strengths

• Contains data for 86,933 stars, nearly doubling the original Henry Draper Catalog's coverage for fainter magnitudes.
• Positions have an accuracy of 0.5 arcseconds, and proper motions for over 96% of stars have a typical accuracy of 5.5 milliarcseconds per year.
• Derived from a historically significant but underutilized source (the HD Extension Charts), providing a bridge to modern data.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• The core catalog excludes an expanded list of over 500 variable star identifications and entries with uncertain identifications, which are in a separate file.

Provenance

Source

Harvard College Observatory (original data), Nesterov et al. 1995 (digitized catalog), NASA HEASARC (host).

Collection Method

Original spectral classifications from photographic charts were converted to a digital catalog using measurements of Cartesian coordinates and cross-identification with the Astrographic Catalog.

Time Range

Original observations and classifications published between 1937 and 1949; catalog digitized in the 1990s.

Freshness

Last updated 2026-03-13 17:17:50.471588; freshness should be verified.

Geography

Celestial coverage; specific regions are not stated.