6.3 Catalogues
71
numbers are a representation of an item’s right ascension and declination. Hence, α
Orion is known as 2MASS J05551028+0724255 in 2MASS.
The NGC and IC Catalogues
The New General Catalogue of Nebulae and Clusters of Stars (NGC) is a catalogue
of nonstellar sources undertaken by the Danish-Irish astronomer John Louis Emil
Dreyer in 1888. The catalogue contains a large number of galaxies that at the time
were not fully understood, as well as star clusters and nebulae. In all, the NGC
contains 7,840 objects, including all of those in the Messier Catalogue. NGC objects
are numbered and prefixed with NGC; hence M31 is also known as NGC 224. The
NGC catalogue was later supplemented by two further catalogues by Dreyer, known
as the Index Catalogues (IC), which together add a further 5,386 objects, which are
prefixed IC.
Uppsala General Catalogue
The Uppsala General Catalogue (UGC) is a northern hemisphere catalogue of bright
galaxies down to magnitude 14.5, which should be within the reach of most northern
teaching observatories equipped with a CCD. The UGC contains 2,921 galaxies,
which are prefixed with UGC.
The Burnham, Aitken, and Washington Double Star Catalogues
The Burnham, Aitken, and Washington Double Star Catalogues are a generational
series of double star catalogues initiated by Sherburne Wesley Burnham, who published his catalogue of 13,665 pairs of double stars. Burnham continued observing
double stars, and that further work was included in the Aitken Double Star Catalogue
(ADS), which extends the Burnham catalogue to 17,180 double stars, although like
the Burnham catalogue, it is confined to mostly northern latitudes. Both Aitken and
Burnham have been superseded by the Washington Double Star Catalogue, which
contains 115,769 pairs of double star positions along with magnitudes and spectral types. Each Washington Double Star Catalogue object is denoted by its J2000
position and prefixed with WDS.
Henry Draper Catalogue
The Henry Draper Catalogue (HD) is a comprehensive catalogue of 359,083 (including various extensions) spectrally classified stars undertaken between 1886 and 1949
with a limiting magnitude of around 9, although in some cases it extends to as faint
as magnitude 11. The spectral classification used by Henry Draper in the catalogue is
the basis for the standard OBAFGKM spectrographic classification scheme used by
astronomers and astrophysicists worldwide. Objects are numbered and prefixed HD,
HDC, or HDEC depending on the catalogue version, although objects are numbered
consecutively throughout all versions and supplements in order to avoid confusion.
For example, α Orion is known as HD 39801 in the Henry Draper Catalogue.
General Catalogue of Variable Stars
The General Catalogue of Variable Stars (GCVS) and its sister catalogue, the New
Catalogue of Suspected Variable Stars, are catalogues of, not surprisingly, variable,
or suspected variable, stars. The GCVS lists the star’s position and the class of
71
numbers are a representation of an item’s right ascension and declination. Hence, α
Orion is known as 2MASS J05551028+0724255 in 2MASS.
The NGC and IC Catalogues
The New General Catalogue of Nebulae and Clusters of Stars (NGC) is a catalogue
of nonstellar sources undertaken by the Danish-Irish astronomer John Louis Emil
Dreyer in 1888. The catalogue contains a large number of galaxies that at the time
were not fully understood, as well as star clusters and nebulae. In all, the NGC
contains 7,840 objects, including all of those in the Messier Catalogue. NGC objects
are numbered and prefixed with NGC; hence M31 is also known as NGC 224. The
NGC catalogue was later supplemented by two further catalogues by Dreyer, known
as the Index Catalogues (IC), which together add a further 5,386 objects, which are
prefixed IC.
Uppsala General Catalogue
The Uppsala General Catalogue (UGC) is a northern hemisphere catalogue of bright
galaxies down to magnitude 14.5, which should be within the reach of most northern
teaching observatories equipped with a CCD. The UGC contains 2,921 galaxies,
which are prefixed with UGC.
The Burnham, Aitken, and Washington Double Star Catalogues
The Burnham, Aitken, and Washington Double Star Catalogues are a generational
series of double star catalogues initiated by Sherburne Wesley Burnham, who published his catalogue of 13,665 pairs of double stars. Burnham continued observing
double stars, and that further work was included in the Aitken Double Star Catalogue
(ADS), which extends the Burnham catalogue to 17,180 double stars, although like
the Burnham catalogue, it is confined to mostly northern latitudes. Both Aitken and
Burnham have been superseded by the Washington Double Star Catalogue, which
contains 115,769 pairs of double star positions along with magnitudes and spectral types. Each Washington Double Star Catalogue object is denoted by its J2000
position and prefixed with WDS.
Henry Draper Catalogue
The Henry Draper Catalogue (HD) is a comprehensive catalogue of 359,083 (including various extensions) spectrally classified stars undertaken between 1886 and 1949
with a limiting magnitude of around 9, although in some cases it extends to as faint
as magnitude 11. The spectral classification used by Henry Draper in the catalogue is
the basis for the standard OBAFGKM spectrographic classification scheme used by
astronomers and astrophysicists worldwide. Objects are numbered and prefixed HD,
HDC, or HDEC depending on the catalogue version, although objects are numbered
consecutively throughout all versions and supplements in order to avoid confusion.
For example, α Orion is known as HD 39801 in the Henry Draper Catalogue.
General Catalogue of Variable Stars
The General Catalogue of Variable Stars (GCVS) and its sister catalogue, the New
Catalogue of Suspected Variable Stars, are catalogues of, not surprisingly, variable,
or suspected variable, stars. The GCVS lists the star’s position and the class of