Période photométriqe de l'étoile Ap HR 3831

From 32 observations made in February 1977, in the uvby system, a photometric period P = 1.428 + or - 0.005 day was previously found for the A7p SrCrEu star HR 3831 = HD 83368. A series of 26 measurements in December 1975, a few measurements in December 1978, both also in the Stromgren system, and the measurements recently published by Kurtz (1982) in B and V (Johnson system) improve the precision on P. The value obtained is P = 1.42602 + or - 0.00006 day. The photometric variations with this period are displayed. As found previously, a null-wavelength appears in the blue. Kurtz's suggestion that the photometric period is equal to twice the value above does not seem to be justified; however, other considerations favor a rotation period equal to twice the photometric one.