Photometric properties of the   Scuti star BR Cancri

Abstract

We present the results of a three-year Johnson V and Stro Èmgren uvbyHb photometric study of the d Scuti star BR Cancri (BR Cnc). Our data sets consist of 1293 discrete differential magnitudes in Johnson V and yellow y filters, 883 in Stro Èmgren v and 239 in ub filters. The Fourier analysis of the data suggests four pulsation frequencies for the variable: f 1 24:978; f 2 11:358; f 3 11:808 and f 4 27:914 cycle d 21 : During the three observing years, the main frequency f 1 kept its V(y) amplitude constant at about 6 mmag but its v amplitude seems to be changing. Amplitude variations for all the three other frequencies are also claimed. The pulsation modes of the frequencies are discussed based on the colour data. Using uvbyb data and calibrations in the literature, we derive the physical parameters for BR Cnc.

Period and amplitude variations in the high-amplitude δ Scuti star AE Ursae Majoris

“…The frequency analysis was performed using PERIOD98 (Breger 1990;Sperl 1998) and MFA (Hao 1991;Liu 1995). We refer the reader to Zhou et al (1999Zhou et al ( , 2001b for the procedure. The solutions for the six sets of data and their bins are highly consistent.…”

“…The detailed technical features of the CCD system have been described in Wei et al (1990). The procedures of data reduction including on-line bias subtraction, dark reduction and flatfield correction, are outlined in Zhou et al (2001a).…”

Stability in Period and Amplitude: The High-Amplitude δ Scuti Star YZ Boötis

“…The frequency analysis was performed using PERIOD98 (Sperl, 1998) and MFA (Hao, 1991;Liu, 1995). We refer the reader to Zhou et al (2001b) for the procedure. The amplitude spectra and the prewhitening procedures for the 2000-2003 data set are given in Figure 1.…”

A δ Scuti Variable in the α Persei Cluster: V459 Per

“…New photoelectric photometry was obtained with the 85 cm reflecting telescope. The instrument employed was the three-channel photoelectric photometer P45-A, the same one used in the Whole Earth Telescope campaign (Nather et al 1990;Jiang & Hu 1998;Zhou et al 2001). P45-A was equipped with a standard Johnson UBV filter system and an ST-6 camera for guiding.…”