The short time-scale light variability of HD 153919 revisited

Abstract

Using Fourier analysis techniques, we have analysed all the available sets of visual photometric data concerning the X-ray binary HD 153919. This was made in order to clear up the controversy on the possible existence or absence of the small amplitude light variability (T∼90 min). In this work, great effort has been made to keep a good level of homogeneity and objectivity. The main conclusion is that at the 99.4% confidence level, a periodicity (ν=15.5 day−1) is detected in one data set. In this case, we can safely conclude that the short time-scale variability does exist! No other self-conclusive detection can be definitely reported; nevertheless, at the 90% confidence level, the star has a tendency to vary with characteristic frequencies of ν∼15 day−1, ν∼30 day−1 and possibly higher multiples.