|
Journal of Physical Studies 20(3), Article 3901 [11 pages] (2016)
DOI: https://doi.org/10.30970/jps.20.3901 PHYSICAL CHARACTERISTICS AND EVOLUTIONARY FEATURES OF PLANETARY NEBULAEYu. F. Malkov, A. V. Demchyna, V. V. Holowatyy
Astrophysics Department, Ivan Franko National University of Lviv, |
 |
A method for determination planetary nebulae optical thickness, central stars temperatures and radiation dilution is elaborated. The values of $\tau_0$ (H$^0$), $\tau_0$ (He$^0$), $\tau_0$ (He$^+$), $T_*$, and $W$ are determined for 116 planetary nebulae. The problem of the connection of $\tau_0$ ($X^i$) with other physical parameters of nebulae and its central stars is discussed. Quantitative changes of $\tau_0$ ($X^i$) at the evolution of nebulae are revealed. It is shown that at the initial stage of evolution of these objects $\tau_0 ({\rm H}^0) \ll 1$, $\tau_0 ({\rm He}^+) \gg 1$ and at the final stage $\tau_0 ({\rm H}^0) \geq l$, $\tau_0 ({\rm He}^+) \leq 1$. The problem of the planetary nebulae envelope masses is discussed in detail. Evolutionary dependences of the nebulae mass on its radius is revealed: $M_i/M_\odot = 0.309 \cdot r^{0.858}$. It is shown that the evolutionary increasing of the nebulae mass can be caused by the raking of the nebular envelope of the star-predecessor wind matter. A quantitative study of this process is done and the movement of nebulae envelopes and its interaction with star wind of star-processor is studied. The question of forming of the planetary nebulae is touched upon. The stellar wind features of the star-predecessor and the evolutionary increasing of the nebula mass are discussed in detail. In the following works we plan to continue the investigation of the physical parameters of the planetary nebula as well as the correlation between them during the evolution of the planetary nebula envelope.
PACS number(s): 98.38.Ly, 98.58.Li