The Object Catalogues
- Cr — Collinder: The Swedish astronomer, Per Collinder, studied the structure and distribution of open galactic clusters. His 1931 catalogue was an appendix to one of his papers.
- IC — Index Catalogue: This is actually a combination of two catalogues, published in 1896 and 1905, of nebulae and double stars. It was compiled by Johan Dreyer, a Danish astronomer who worked in Ireland (Parsonstown and Dublin). It is a supplement to his NGC.
- M — Messier: Charles Messier’s catalogue (augmented by Pierre Méchain) of objects for comet-hunters to avoid as they sought the return of Halley’s comet. It was first published in 1771 and was updated for ten years.
- Mel — Melotte: Philibert Jacques Melotte was a British astronomer of Belgian descent; amongst many astronomical achievements, in 1915 he published his eponymous catalogue of open clusters.
- NGC — New General Catalogue: This was compiled by Johan Dreyer and published in 1888, based on observations by William, Caroline and John Herschel, and James Dunlop. It is a massive work (7840 objects), but contains many errors, some of which still remain after several revisions.
- Σ — Struve: This is a catalogue of double stars that was published in 1837. It was compiled by Friedrich Georg Wilhelm von Struve, a German-born astronomer who founded the Pulkovo Observatory near St Petersburg.