IRAS 18062+2410: An early formation stage of a planetary nebula

The photometric and spectroscopic observations of IRAS 18062+2410 = V886 He r, a candidate for protoplanetary objects, in 1996-1997 are presented. The star exhibits irregular rapid light variations with an amplitude up to 0.(m )3 in I! Its variability is similar in pattern to the light variations in P V Tel stars. A high-resolution spectrum of IRAS 18062+2410 shows absorption lines of a hot B supergiant and numerous emission lines of H, He I, O I, F e II, Si II, Na I, and other species, including [O II], [N II], and [Fe II] that belong to the stellar envelope. Presently, the stellar spectrum can b e classified by the absorption lines and by the continuum spectral energy d istribution in the wavelength range 400-9000 Angstrom as B1-1.5 II. The sta r is shown to have been evolved markedly over the last 150 years. A compari son of the observational data with theoretical evolutionary tracks of post- AGE stars yields an estimate 0.70 +/- 0.01 M. for the stellar mass, The mas s of the envelope's ionized part and its radius are estimated to be similar to 10(-3) M. and similar to 10(-2) PC, respectively.