Photometric researches
Subtitle: the eclipsing variable Y Cygni
By: by Raymond Smith Dugan.
Series: Contributions from the Princeton University Observatory -- no. 12.
Publisher: The Observatory
Published: 1931
Place of publication: Princeton, N.J
Language: eng; dan
Number of pages: 50
Subjects: Variable stars.; Stars -- Spectra.
Notes: Bibliography: p. 5-11.