An investigation of planetary nebulae accompanying PG 1159 central stars, based on Gaia DR2 measurements

Abstract

This article discusses the physical and kinematical characteristics of planetary nebulae accompanying PG 1159 central stars. The study is based on the parallax and proper motion measurements recently offered by the Gaia space mission. Two approaches were used to investigate the kinematical properties of the sample. The results revealed that most of the studied nebulae arise from progenitor stars in the mass range 0.9-1.75 M o˙. Furthermore, they tend to live within the Galactic thick disk and move with an average peculiar velocity of 61.7 ± 19.2 km s-1 at a mean vertical height of 469 ± 79 pc. The locations of the PG 1159 stars on the H-R diagram indicate that they have an average final stellar mass and evolutionary age of 0.58 ± 0.08 M o˙ and 25.5 ± 5.3 × 103 yr, respectively. We found a good agreement between the mean evolutionary age of the PG 1159 stars and the mean dynamical age of their companion planetary nebulae (28.0 ± 6.4 × 103 yr).