Dictionary of Nomenclature of Celestial Objects

 
byABELL G.O.
 Publ. Astron. Soc. Pac., 67, 258-261 (1955)
  Globular clusters and planetary nebulae discovered on the national geographic society-Palomar Observatory sky survey.
oTable I: <Cl Palomar NN> (Nos 1-13), Table II: <PN A55 NN> (Nos 1-73)

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