Plan of selected areas
By: by J.C. Kapteyn ... Pub. by the Astronomical laboratory at Groningen.
Contributors: Rijksuniversiteit te Groningen. Sterrekundig laboratorium.
Publisher: Hoitsema brothers
Published: 1906
Place of publication: Groningen
Language: eng
Number of pages: 82
Subjects: Stars.
Notes: A plan for investigating the distribution of stars according to photographic and visual magnitudes, and in which 20,000 stars are to be investigated for proper motion and parallax, and the class of spectrum determined and radial velocity measured for as many as possible.