CCD Photometry of the RR Lyrae Star AH Camelopardalis (Abstract)

Volume 21 number 1 (1992)

Horace A. Smith

Michigan State University, Department of Physics and Astronomy, East Lansing, MI

K. M. Lee

Michigan State University, Department of Physics and Astronomy, East Lansing, MI

N. A. Silbermann

Michigan State University, Department of Physics and Astronomy, East Lansing, MI

J. S. Williams

Michigan State University, Department of Physics and Astronomy, East Lansing, MI

J. Matthews

University of Montreal, Department of Physics, Montreal, Canada

M. Bolte

UCO/Lick Observatory, University of California, Santa Cruz, Santa Cruz, CA

Abstract

(Abstract only) We have used the Michigan State University 0.6-m telescope to obtain CCD photometry of the RR Lyrae star AH Cam. About 750 V-band observations were obtained in the 1989-1990 and 1991-1992 observing seasons. These observations confirm that the light curve of AH Cam does not repeat precisely form cycle to cycle. The most likely explanation of these light curve variations is that AH Cam has a secondary Blazhko cycle of about 10.8 days. The existence of such a Blazhko cycle was earlier suggested by Goranskij (1989). This is the shortest known secondary cycle of the classic Blazhko type among RR Lyrae variables. The short primary period of AH Cam, 0.36873 day, is characteristic of RRab variables which are relatively rich in heavy elements. A spectrum lf AH Cam, obtained at the Dominion Astrophysical Observatory, confirms that AH Cam does belong to the group of relatively metal-rich RR Lyrae stars. Reference: Goranskij, V. P. 1989, Sov. Astron. 33, 45.