Infrared properties of planetary nebulae with [WR] central stars

¹ Copernicus Astronomical Centre, Department for Astrophysics, Rabiańska 8, 87-100 Toruń, Poland
² Observatoire de Paris-Meudon, DAEC, 92195 Meudon Cedex, France

Corresponding author: S. K. Górny, skg@ncac.torun.pl

Received: 9 October 2000
Accepted: 16 July 2001

Abstract

We have gathered from the literature near and mid infrared (photometric and spectroscopic) data for Galactic planetary nebulae, with special attention to planetary nebulae surrounding Wolf-Rayet type central stars ([WR] PN). These data have been analyzed to obtain insight into the dust-properties of [WR] PN and their evolutionary status. We have found that a sizeable fraction of [WR] PN seems to contain hot dust (1000-2000 K), probably located in the winds of the central stars. The mean dust temperature is shown to decrease with decreasing [WC] spectral type. This is in line with suggestions that the [WC] sequence is an evolutionary sequence from late to early types. [WR] PN in different diagrams, when compared to those of non-[WR] PN, suggest that [WR] PN form a homogeneous class of planetary nebulae. There is an unusually large proportion of [WR] PN showing PAH features in their spectra.