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|Citation||Perrine, C.D. (1930) Observations of Planetary Nebulae wanted. AN, 237, 351.|
Evidence has been encountered which leads to the belief that the planetary nebulae may be expanding and contracting with sufficient rapidity to be detected within the period of modern observations.
In order to investigate this point more fully all accurate observations of diameters, whether visual with the micrometer or of photographs, are desired. Any such unpublished observations including the novae, will be very welcome.
Observatorio Nacional Argentino, Cordoba, July 12, 1929
Document type: Journal article.
Document source: SAAO Library
Scope: Complete article.
Keyed in: AS
Proof reading: AS
Online version: 2010 August 19.
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