Physical and Kinematical Characteristics of Wolf–Rayet Central Stars and their Host Planetary Nebulae

Abstract

We addressed the physical and kinematical properties of Wolf-Rayet [WR] central stars (CSs) and their hosting planetary nebulae (PNe). The studied sample comprises all [WR] CSs that are currently known. The analysis is based on recent observations of the parallax, proper motion, and color index of [WR] CSs from the Gaia space mission's early third release (eDR3) catalog, as well as common nebular characteristics.
The results revealed an evolutionary sequence, in terms of decreasing T$_{\text{eff}}$, from the early hot [WO 1] to the late cold [WC 12] stars. This evolutionary sequence extends beyond [WR] CS temperature and luminosity to additional CS and nebular characteristics.
The statistical analysis showed that the mean final stellar mass and evolutionary age of the [WR] CS sample are 0.595 $\pm$ 0.13\,M$_{\odot}$ and 9449 $\pm$ 2437\,yr, respectively, with a mean nebular dynamical age of 7270 $\pm$ 1380\,yr.
In addition, we recognized that the color of the majority ($\sim$ 85\%) of [WR] CSs tends to be red rather than their genuine blue color. The analysis showed that two-thirds of the apparent red color of most [WR]s is attributed to the interstellar extinction whereas the other one-third is due to the PN self-extinction effect.