The Very Fast Evolution of V4334 Sgr

P.A.M. Hoof; G.C. Van de Steene; S. Kimeswenger; A.A. Zijlstra; M. Hadjuk; F. Herwig

doi:10.1051/eas/1571064

All issues

Volume 71-72 (2015)

EAS Publications Series, 71-72 (2015) 287-288

Abstract

Issue		EAS Publications Series Volume 71-72, 2015 The Physics of Evolved Stars: A Conference Dedicated to the Memory of Olivier Chesneau


Page(s)		287 - 288
Section		Circumstellar Environments
DOI		https://doi.org/10.1051/eas/1571064
Published online		01 December 2015

The Physics of Evolved Stars: A Conference Dedicated to the Memory of Olivier Chesneau
E. Lagadec, F. Millour and T. Lanz (eds)
EAS Publications Series, 71–72 (2015) 287-288

The Very Fast Evolution of V4334 Sgr

P.A.M. Hoof¹, G.C. Van de Steene¹, S. Kimeswenger², A.A. Zijlstra³, M. Hadjuk⁴ and F. Herwig⁵

¹ Royal Observatory of Belgium, Brussels, Belgium
² Universidad Católica del Norte, Antofagasta, Chile
³ Jodrell Bank Centre for Astrophysics, Manchester, UK
⁴ Nicolaus Copernicus Astronomical Center, Torun, Poland
⁵ University of Victoria, Victoria, Canada

Abstract

V4334 Sgr (Sakurai*s object) is an evolved star that underwent a very late thermal pulse ejecting a new, hydrogen-deficient nebula inside the old planetary nebula. From 2001 through 2007 the emission lines from the new nebula showed an exponential decline in flux, consistent with a shock that occurred around 1998 and started cooling soon afterwards. Since 2008 the line fluxes have been continuously rising again. Our preliminary interpretation is that this emission comes from a region close to the central star, and is excited by a second shock, which may have been induced by an increase in the stellar mass loss and wind velocity associated with a rise in the stellar temperature.