Palomar-Green Catalog: UV-Excess Stellar Objects with Spectral Types

1,874 stellar objects with ultraviolet excess were cataloged from photographic plates taken with the Palomar 18-inch Schmidt telescope. The catalog provides positions, magnitudes, spectral types, and color data, with a statistically complete sample of 1,715 objects covering 10,714 square degrees. NASA HEASARC hosts this version, which includes updates from 2009 providing more precise coordinates.

Use Cases

• Classifying stellar populations based on provided spectral types and color data.
• Studying the distribution and properties of hot subdwarf (sdB) stars, which comprise nearly 40% of the sample.
• Identifying and analyzing white dwarfs (DA, DB, DO, DC, DZ types) based on their cataloged spectral classifications.
• Researching extragalactic objects, particularly quasars, which represent 5.4% of the complete sample.
• Conducting statistical sky surveys using the complete sample covering 10,714 square degrees.

Strengths

• Contains a statistically complete sample of 1,715 objects covering 10,714 square degrees from 266 fields.
• Provides specific population percentages: ~40% sdB stars, 21% DA white dwarfs, 5.4% QSOs.
• Includes updated sub-arcsecond positional accuracy and V magnitudes from a 2009 addition.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• The overall completeness is estimated at 84%, but this figure varies depending on magnitude and color distribution.
• Limiting magnitudes vary from field to field, ranging from 15.49 to 16.67.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC), based on CDS catalog II/207A.

Collection Method

Compiled from photographic plates taken with the Palomar 18-inch Schmidt telescope.

Time Range

Catalog published in 1986, with updates notably in 2009 and 2017.

Freshness

Last updated 2026-03-13 18:07:38.819621; freshness should be verified.

Geography

Sky survey covering 10,714 square degrees.