The keywords listed below are required or recommended for all FITS files in both primary (P) and extension (E) headers that contain catalogs.

The following table(s) of HLSP metadata, to be included in science products, are color-coded:




File headers must also include the basic structural FITS keywords and the list of common keywords.


BUNITEBrightness unit for array values

RADESYSEMnemonic for celestial coordinate reference system (typically 'FK5' or the  preferred 'ICRS').

<Filt>MAG0EFlux corresponding to zero magnitude in the <Filt> passband. Note that the last character is a capital "oh", not a zero.

Catalog Fields

Most of the metadata in catalogs is often in the definition of the database fields, or table column names, units, and numeric types. Below are the recommended fields for source catalogs, where text in brackets is entirely user-defined.


DECdoubleDeclination coordinate of source

RAdoubleRight ascension coordinate of source

SOURCEstringAlphanumeric identifier of source

<Filt>floatBrightness of source in the passband named <Filt>, with NULL value (NaN) indicating no measurement

<Filt>_errfloatUncertainty in source brightness.

<Filt>_flagintApplicable, encoded flags that apply to the brightness in the named passband, with the convention that zero indicates no pathologies.

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