A search for photometric and spectroscopic evolutionary changes in the young planetary nebula Vy 2-2

The results of long-term photometric and spectroscopic observations of the young compact planetary nebula Vy 2-2 (PNG 045.4-02.7) are presented. The UBV photometry in 1990-2016 has revealed a slight brightness trend in the yearly averaged data, most pronounced in the V band. We have measured the relative fluxes of optical emission lines on the spectrograms taken with the 1.25-m telescope at the Southern Station of the SAI MSU in 1999-2016, estimated the absolute flux in the H beta line to be F(H beta) = (2.1 +/- 0.4) x 10(-12) erg cm(-2) s(-1), and determined the interstellar extinction constant c(H beta) = 1.8. The electron temperature and density in the nebula have been estimated from diagnostic line ratios: T-e = (10-12) x 10(3) K and Ne >= 10(5) cm(-3). To detect any possible evolutionary changes, we have compared the new observations with the archival data obtained over the entire history of spectroscopic observations of Vy 2-2. No significant changes in the relative intensities of the strongest emission lines and the integrated flux in the H beta line exceeding the observational errors have been found. We have revealed a tendency for the intensity ratio F(lambda 4363)/F(lambda 4959) to decrease with time, which may be related to a decrease in the electron density in the nebula. Based on our photometric and spectroscopic data, we have estimated the luminosity of the central star of Vy 2-2, which corresponds to the evolutionary tracks for the most massive post-AGB stars of the O-rich sequence.