AAS 199th meeting, Washington, DC, January 2002
Session 90. $\delta$ Scuti and Mira Variables
Display, Wednesday, January 9, 2002, 9:20am-6:30pm, Exhibit Hall

## [90.02] 4CVN: Amplitude Variability in 1990-1991

K. A. Davis, R. J. Dukes Jr. (College of Charleston)

4 CVn is one of the most extensively studied of the Delta Scuti stars. We observed it with Four College Consortium Automatic Photometric Telescope during the 1990-91 season. Due to a problem with the comparison star the data were not analyzed. In 1996 it was the subject of a Whole Earth Telescope (WET) campaign (Breger, et. al 1999) which found 30+ frequencies. Breger (2000) collected all observations over the last 30 years and studied the amplitude variation frequencies found in the 1996 campaign. A serious gap occurs in this data from 1984 - 1996. Since our data is in the middle of this gap we have reduced it with respect to the check star. We applied similar techniques using Period98 (Sperl 1998) to find frequencies in the WET analysis. We found many of these frequencies and calculated their amplitudes. The amplitudes presented here will further the understanding of the amplitude variability of the Delta Scuti star 4CVn. We acknowledge support of NSF grants AST-0071260 and AST-8616362 to the College of Charleston.