SIMBAD references

BW Vulpeculae (BW Vul) has the largest amplitude of the beta Cephei stars. Over almost 80 years of observations, BW Vul has closely followed a parabolic ephemeris and possibly a light-travel-time effect. This parabola, with excursions on either side, also could be viewed as a sequence of straight lines (constant period) with abrupt period increases. This paradigm predicted a period increase around 2004, which did not occur. A recent observing campaign on this star using the AAVSOnet's Bright Star Monitor telescopes as well as the 0.7-m Lowell Observatory telescope has been undertaken. A period analysis of our data suggests that the period may have paradoxically decreased beginning around 2009. Further observations are necessary to confirm this analysis.