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The Stellar Content of the Perseus Galactic Arm in the Region of h and Chi Persei


Wildey, Robert LeRoy (1962) The Stellar Content of the Perseus Galactic Arm in the Region of h and Chi Persei. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/TNJ1-XF88.


A total of 944 stars in the general region of h and chi Persei in the Perseus Galactic arm have been observed photometrically in U, B, and V of the Johnson-Morgan photometric system. Supergiants, O stars, giants, subgiants, and their fainter immediate neighbors (used to obtain reddenings) totaling 336 stars have been measured photoelectrically in the general OB association of which the galactic clusters form the nucleus. Within the extreme nuclei of the clusters-proper, photoelectrically calibrated photographic observations have been made with completeness down to about 18th magnitude on an additional 608 stars; however, the photoelectric limit is V = 17. 0. Fine structure is exhibited by the stars above the vertical main sequence and a slightly fainter red off-shoot is found. A sequence of stars is found in apparent gravitational contraction but with main-sequence stars extending, nevertheless, to the observational limit. At present the data is best represented by theories of gravitational contraction, hydrogen-burning, and helium-burning, together with a non-unique epoch of stellar condensation. Contraction and nuclear time-scales for the different features are compatible. The differences in apparent evolutionary tracks between the Galaxy, LMC, and SMC are reconfirmed. The 2-color diagram of the bluest stars is of a gray-body character. Sp vs (B-V)[subscript o] is monotonic for all stars. The M supergiants are shifted red-ward over previous studies and form a steep 2-color relation.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Astronomy)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Astronomy
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Arp, Halton C. (advisor)
  • Sandage, Allan R. (advisor)
Group:Astronomy Department
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1962
Record Number:CaltechETD:etd-09232008-080747
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3731
Deposited By: Imported from ETD-db
Deposited On:06 Nov 2008
Last Modified:27 Nov 2023 21:26

Thesis Files

PDF (Wildey_rl_1962.pdf) - Final Version
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