A search for period changes in δ Scuti stars with the super-LOTIS sky patrol system

¹ Division of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125, USA
² Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
³ Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA
⁴ Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA

Corresponding author: C. Blake, Cblake@princeton.edu

Received: 17 September 2002
Accepted: 5 November 2002

Abstract

We have observed a sample of δ Scuti stars discovered by the ROTSE collaboration in 1999 with Super-LOTIS in order to characterize changes in their pulsation periods over a time baseline of roughly three years. Achieving these goals required the creation of an automated astrometric and photometric data reduction pipeline for the Super-LOTIS camera. Applying this pipeline to data from a June 2002 observing campaign, we detect pulsations in 18 objects, and find that in two cases the periods have changed significantly over the three years between the ROTSE and Super-LOTIS observations. Since theory predicts that evolutionary period changes should be quite small, sources of non-evolutionary period changes due to the interactions of pulsations modes are discussed.