A massive parsec-scale dust ring nebula around the yellow hypergiant Hen 3-1379

¹ Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 août 17, B5c, 4000 Liège, Belgium
e-mail: hutsemekers@astro.ulg.ac.be
² Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium

Received: 28 February 2013
Accepted: 15 March 2013

Abstract

On the basis of far-infrared images obtained by the Herschel Space Observatory, we report the discovery of a large and massive dust shell around the yellow hypergiant Hen 3-1379. The nebula appears as a detached ring of 1 pc diameter which contains 0.17 M_⊙ of dust. We estimate the total gas mass to be 7 M_⊙, ejected some 1.6 × 10⁴ years ago. The ring nebula is very similar to nebulae found around luminous blue variables (LBVs) except it is not photoionized. We argued that Hen 3-1379 is in a pre-LBV stage, providing direct evidence that massive LBV ring nebulae can be ejected during the red supergiant phase.