Contents within planetarium

• 444 open clusters
• 10 globular clusters
• 7 duplicate catalogue entries
• 5 nebulae
• 1 galaxy
• 1 asterism
• 1 nebula

Overlap with other object catalogs

• 321 New General Catalogue (NGC)
• 156 Melotte catalog
• 31 Messier objects
• 29 Caldwell objects
• 21 Index Catalogue (IC)
• 18 Lynds' catalogue of bright nebulae
• 3 Van den Bergh catalogue of reflection nebulae
• 1 Uppsala General Catalog of galaxies (UGC)
• 1 Principal Galaxies Catalogue
• 1 PK planetary nebulae
• 1 Markarian galaxies

Reference

• https://ui.adsabs.harvard.edu/abs/1931AnLun...2....1C

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