STERKEN C., ARENTOFT T., DUERBECK H.W. and BROGT E.
Abstract (from CDS):
Stroemgren differential photometry of HD 168607 and HD 168625 collected during the previous 27 years is analysed. We bring to an end our quarter of a century monitoring of these objects and conclude that HD1 68607 shows typical variability of an uneventful LBV, whereas HD 168625 remains to be classified as a variable hypergiant, or a marginally-dormant LBV. The long-term light- and colour behaviour of HD 168607 indicates the possible presence of a very slowly-developing S Dor phase - that is, a bright phase that coincides with redder colours. Besides the α Cygni-type microvariability, no other signs of ultrashort-periodic variability has been observed.
stars: early-type - stars: individual: HD 168607 - stars: individual: HD 168625 - stars: oscillations - stars: variables: general