Light variations of massive stars (alpha Cygni variables). XIII. The B-type hypergiants R 81 (LBV), HD 80077 (LBV?), HD 168607 = V 4029 Sagittarii (LBV) and HD 168625 = V 4030 Sagittarii.

We present and discuss VBLUW and uvby photometry of four Alpha Cyg variables: the B-type hypergiants R81, HD 80077, HD 168607 = V 4029 Sgr, and HD 168625 = V 4030 Sgr. Quasi-periods of the light variations amount to 24,41 or 55,58 and 35 days, respectively. The maximum light amplitude (MLA) of R 81 and HD 168607 clearly reflects their LBV character. That for HD 80077 suggests that it could be an LBV also. Normal Alpha Cyg variables and those which suffer from episodic mass loss eruptions, the LBVs appear to listen to the same P = constant lines in the HR diagram, but the light curves of both types show morphological differences.