Revised Period for CT Orionis

Volume 15 number 2 (1986)

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Daniel H. Horowitz
5930 Sanford Road, Houston,

Abstract

The star CT Orionis is listed in the GCVS as an RV Tauri variable with a period of 135.52 days. Based on a year of study, during which an AAVSO chart was prepared, a revised period of at most 66 and quite likely as short as 33 days was determined. There is a hint that the light curve exhibits alternating deep and shallow minima which is a characteristic of RV Tauri variables. However, the difference in the magnitudes of alternate minima are quite small and lie within the range of observational error, so a 33-day period with a Cepheid-like pattern is also likely. Additional observations are needed to decide if CT Orionis should be reclassified or if it is an RV Tauri member that might possibly be experiencing atypical behavior.