The distances of planetary nebulae: A scaling factor based upon radial velocities

Instituto de Astronomia y Meteorologia, Avenida Vallarta 2602, Col. Arcos Vallarta, CP 44130 Guadalajara, Jalisco, Mexico

Corresponding author: J. P. Phillips, jpp@udgserv.cencar.udg.mx

Received: 19 May 2000
Accepted: 1 December 2000

Abstract

We have used the observed radial velocities of planetary nebulae, and the galactic rotation curve to define a new distance scale for planetary nebulae. Care has been taken to restrict the analysis to sources in which distance non-linearities are minimised, and for which distortion of the distance scale is likely to be small. We conclude, as a result, that the so-called "long"distance scales are the most valid, and that various "shorter"scales are unlikely to be correct. The primary systematic errors in this procedure derive from uncertainties in the galactic rotation profile, and in and R₀. Such errors are less than those normally associated with PN distance determinations.