The variability of hot protoplanetary objects and the stellar wind from central stars of planetary nebulae

The results of longtime systematic UBV-observations of 6 hot protoplanetary nebulae (PPN) with early B spectra are given. Fast stochastic brightness variations in the range of 0.$^m$2-0.$^m$4 (in $V$-band) have been found. The minimal time scale of the oscillations is from several hours to one day. The repeated spectral observations of hot protoplanetary nebulae have shown obvious variability in the hydrogen emission lines. It is suggested that the stellar wind from the future planetary nebula nucleus with variable $\dot{M}$ is responsible for variations observed in hot PPNs.