Nuova variabile 33.1907 Persei (BD +49°499)

New observations of 53 Persei

We gathered 37 new spectra of the B star 53 Persei spread over approximately 2 years. On these data, we performed a frequency and a mode analysis. We determined the physical parameters of 53 Persei and placed the star in the theoretical SPB instability strip. We also analysed the 110 photometric observations of the Hipparcos satellite. Our results show the presence of the two frequencies often ...

On the polarization of φ Persei

Polarimetric data of φ Per from recent observations with the HPOL spectropolarimeter and from an earlier study in the literature have been compared. It is shown that for measurements with accuracies ∆p ∼ 0.003%, temporal changes are readily detected, these seemingly being unrelated to periodic changes in scattering geometry associated with the binary nature of the star. From studies of the p(λ)...

The Double-Mode Cepheid V371 Persei Redux

A metallicity of 1⁄2Fe=H 1⁄4 0:05 to 0:40 was derived from four spectra of the peculiar beat Cepheid V371 Per. This conflicts with previous estimates ranging from 0:7 to 1:0 based on the period ratio. It is suggested that the discrepancy may be resolved by assuming near solar metallicity but a low mass. This is in accord with a suggestion by Sandage and Tammann that the AHB3 (or BL Her) stars a...

53 Persei : a slowly pulsating B star ?

A new investigation of the behaviour of the star 53 Per was performed. New photometric observations allow to confirm twodominant periods p1=2.16 d, p2= 1.67 d.A third one p3= 3.64 d is detected. These long period variations are present in our radial velocities data and in old equivalent width data. The amplitude of the p1 = 2.16 d period increases from 1977 to 1991, while the amplitude of the 1...

On bD-Sets and Associated Separation Axioms