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GJ, Gliese, Gl

The Gliese (later Gliese-Jahreiß) catalogue attempts to list all stars within 20 parsecs of Earth ordered by right ascension (see the List of nearest stars). Later editions expanded the coverage to 25 parsecs. Numbers in the range 1.0–965.0 (Gl numbers) are from the second edition, which was

Catalogue of Nearby Stars (1969, W. Gliese).

The integers up to 915 represent stars which were in the first edition. Numbers with a decimal point were used to insert new stars for the second edition without destroying the desired order (by right ascension). This catalogue is referred to as CNS2, although this name is never used in catalogue numbers.

Numbers in the range 9001–9850 are from the supplement

Extension of the Gliese catalogue (1970, R. Woolley, E. A. Epps, M. J. Penston and S. B. Pocock).

Numbers in the ranges 1000–1294 and 2001–2159 (GJ numbers) are from the supplement

Nearby Star Data Published 1969–1978 (1979, W. Gliese and H. Jahreiß).

The range 1000–1294 represents nearby stars, while 2001–2159 represents suspected nearby stars. In the literature, the GJ numbers are sometimes retroactively extended to the Gl numbers (since there is no overlap). For example, Gliese 436 can be interchangeably referred to as either Gl 436 or GJ 436.

Numbers in the range 3001–4388 are from

Preliminary Version of the Third Catalogue of Nearby Stars (1991, W. Gliese and H. Jahreiß).

Although this version of the catalogue was termed "preliminary", it is still the current one as of March 2006, and is referred to as CNS3. It lists a total of 3,803 stars. Most of these stars already had GJ numbers, but there were also 1,388 which were not numbered (plus the Sun, which needs no number). The need to give these 1,388 some name has resulted in them being numbered 3001–4388 (NN numbers, for "no name"), and data files of this catalogue now usually include these numbers. An example of a star which is often referred to by one of these unofficial GJ numbers is GJ 3021.