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On a Cluster of Nebulae in Hydra

Zwicky, F. (1941) On a Cluster of Nebulae in Hydra. Proceedings of the National Academy of Sciences of the United States of America, 27 (6). pp. 264-269. ISSN 0027-8424.

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Clusters of nebulae are the largest known aggregations of matter which possess definite individual characteristics. In preparation of a theoretical study of the large scale distribution of matter in the universe we propose to analyze some simple structural features of a number of clusters of nebulae. Most of the observational data used were obtained with the 18-inch Schmidt telescope on Palomar Mountain. Photographs taken with this instrument, because of their excellent and uniform definition over a field of about seventy square degrees are well suited for a survey of a number of the more near-by clusters of nebulae. In the present report we shall be concerned with a cluster of nebulae in Hydra. The three nebulae NGC 3285, 3309 and 3312, the apparent magnitudes of which according to the Shapley-Ames catalog are m = 13.2, 12.7 and 13.1, respectively, lie near the line of sight of the center of the cluster (at about R.A. 10h 34m, Decl. -27° 16', epoch 1950). The distribution of the nebulae brighter than about the apparent magnitude m = 16 is shown in figure 1.

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Additional Information:Copyright © 1941 by the National Academy of Sciences Communicated May 2, 1941
Issue or Number:6
Record Number:CaltechAUTHORS:ZWIpnas41
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5686
Deposited By: Archive Administrator
Deposited On:27 Oct 2006
Last Modified:02 Oct 2019 23:25

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