SIMBAD references

A new investigation of the behaviour of the star 53 Per was performed. New photometric observations allow to confirm two dominant periods p₁=2.16d, p₂=1.67d. A third one p₃=3.64d is detected. These long period variations are present in our radial velocities data and in old equivalent width data. The amplitude of the p₁=2.16d period increases from 1977 to 1991, while the amplitude of the 1.67d period remains constant. Considering the observational characteristics of the star since 1997, 53 Per clearly belongs to the Slowly Pulsating B stars group as defined by Waelkens (1991A&A...246..453W) and North & Paltani (1994A&A...288..155N).