PHOTOMETRY OF TYPE II CEPHEIDS. II. THE SHORT-PERIOD STARS

Authors

Edward G. Schmidt, University of Nebraska-LincolnFollow
Dale Johnston, University of Nebraska-LincolnFollow
Shawn Langan, University of Nebraska-LincolnFollow
Kevin M. Lee, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

4-1-2005

Comments

Published in The Astronomical Journal 129, pp. 2007-2017 (April 2005). Copyright 2005 by the University of Chicago Press and the American Astronomical Society. Journal homepage = http://www.journals.uchicago.edu/AJ/
Reproduced by permission of the AAS.

Abstract

We present 668 new photometric observations for 24 Cepheids with periods less than 3 days. Most of the stars are probable type II Cepheids, but we have included some type I Cepheids for comparison. A discussion of the Fourier parameters of the light curves leads to the conclusion that they can be used to distinguish among the several types of light curves found among the type II stars but are of limited usefulness for distinguishing between type I and type II Cepheids. The pulsational stability is investigated by searching for long-term changes in the light-curve shapes, period changes, and light-curve scatter. In terms of these parameters, the pulsation is more stable than those that were found for the long-period stars, but for each there are several stars that show unusually large effects. However, there does not seem to be any obvious difference in light-curve stability of type II Cepheids compared with type I Cepheids.