  Some CP stars have recently been discovered by Catalano et al. (1991) to be
variable also in the near infrared, although with smaller amplitudes than in
the visible. Hence an observational campaign was started in which the infrared
light variability of a number of CP2 and CP4 stars has been investigated at the
ESO-La Silla Observatory in the bands J, H, and K. As a general result,
infrared variations show the same behavior in all three filters but amplitudes
are smaller than in the visible.
