Candidates for giant lobes projecting from the LBV stars P Cygni and R 143

¹ Jodrell Bank Observatory, University of Manchester, Macclesfield SK11 9DL, UK
² Institute of Astronomy & Astrophysics, National Observatory of Athens, I. Metaxa & V. Paulou, P. Penteli, GR-15236 Athens, Greece
³ Dublin Institute for Advanced Studies, School of Cosmic Physics, 5 Merrion Square, Dublin 2, Republic of Ireland
⁴ Instituto de Astronomia, UNAM, Apdo. Postal 877. Ensenada, BC 22800, México
⁵ University of Crete, Physics Department, PO Box 2208, 710 03 Heraklion, Crete, Greece

Corresponding author: J. Meaburn, jm@ast.man.ac.uk

Received: 19 January 2004
Accepted: 6 April 2004

Abstract

Deep, wide-field, continuum-subtracted, images in the light of the Hα + [N ii] 6548 & 6584 Å and [O iii]5007 Å nebular emission lines have been obtained of the environment of the Luminous Blue Variable (LBV) star P Cygni. A previously discovered, receding, nebulous filament along PA 50° has now been shown to extend up to 12´ from this star. Furthermore, in the light of [O iii]5007 Å, a southern counterpart is discovered as well as irregular filaments on the opposite side of P Cygni.
Line profiles from this nebulous complex indicate that this extended nebulosity is similar to that associated with middle-aged supernova remnants. However, there are several indications that it has originated in P Cygni and is not just a chance superposition along the same sight-line. This possibility is explored here and comparison is made with a new image of the LBV star R 143 in the LMC from which similar filaments appear to project.
The dynamical age of the P Cygni giant lobe of ≈5  10⁴ yr is consistent with both the predicted and observed durations of the LBV phases of 50 stars after they have left the main sequence. Its irregular shape may have been determined by the cavity formed in the ambient gas by the energetic wind of the star, and shaped by a dense torus, when on the main sequence. 
The proper motion and radial velocity of P Cygni, with respect to its local environment, could explain the observed angular and kinematical shifts of the star compared with the giant lobe.