A Caltech Library Service

Variable Stars with Periods Greater than One Day in Globular Clusters


Arp, Halton Christian (1953) Variable Stars with Periods Greater than One Day in Globular Clusters. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/SMXJ-NH60.


Nineteen variable stars with periods greater than one day were observed in six globular clusters. The observational techniques and the accuracy of the measurements are discussed and light curves for 15 variables are exhibited. Color-magnitude diagrams for six clusters are presented and the distance modulus to each is derived. The resulting period-luminosity relation for type II cepheids indicates there are actually three separate lines in the period-luminosity diagram which these variables occupy. Means of identifying stars on these different lines are presented. The factor of two in the period which these lines are from each other is discussed from the standpoint of the nature of cepheid variation. Finally a hypothesis is advanced to explain the connection between type I and type II cepheids.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Astronomy and Physics)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Astronomy
Minor Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Baade, Walter
Group:Astronomy Department
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1953
Record Number:CaltechETD:etd-05052003-160207
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1616
Deposited By: Imported from ETD-db
Deposited On:06 May 2003
Last Modified:17 May 2023 22:25

Thesis Files

PDF (Arp_hc_1953.pdf) - Final Version
See Usage Policy.


Repository Staff Only: item control page