000002089 001__ 2089
000002089 005__ 20160706150624.0
000002089 0247_ $$2DOI$$a10.1051/0004-6361/201526578
000002089 037__ $$aASTROimport-246
000002089 100__ $$aMartayan, C.
000002089 245__ $$aLuminous blue variables: An imaging perspective on their binarity and near environment
000002089 260__ $$c2016
000002089 520__ $$aContext. Luminous blue variables (LBVs) are rare massive stars with very high luminosity. They are characterized by strong photometric and spectroscopic variability related to transient eruptions. The mechanisms at the origin of these eruptions is not well known. In addition, their formation is still problematic and the presence of a companion could help to explain how they form.  Aims: This article presents a study of seven LBVs (about 20% of the known Galactic population), some Wolf-Rayet stars, and massive binaries. We probe the environments that surround these massive stars with near-, mid-, and far-infrared images, investigating potential nebula/shells and the companion stars.  Methods: To investigate large spatial scales, we used seeing-limited and near diffraction-limited adaptive optics images to obtain a differential diagnostic on the presence of circumstellar matter and to determine their extent. From those images, we also looked for the presence of binary companions on a wide orbit. Once a companion was detected, its gravitational binding to the central star was tested. Tests include the chance projection probability, the proper motion estimates with multi-epoch observations, flux ratio, and star separations.  Results: We find that two out of seven of LBVs may have a wide orbit companion. Most of the LBVs display a large circumstellar envelope or several shells. In particular, HD 168625, known for its rings, possesses several shells with possibly a large cold shell at the edge of which the rings are formed. For the first time, we have directly imaged the companion of LBV stars. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under projects number 085.D-0625(C), 087.D-0426(C, D), and archival data 383.D-0323(A).The reduced NACO images are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A115
000002089 700__ $$aLobel, A.
000002089 700__ $$aBaade, D.
000002089 700__ $$aMehner, A.
000002089 700__ $$aRivinius, T.
000002089 700__ $$aBoffin, H. M. J.
000002089 700__ $$aGirard, J.
000002089 700__ $$aMawet, D.
000002089 700__ $$aMontagnier, G.
000002089 700__ $$aBlomme, R.
000002089 700__ $$aKervella, P.
000002089 700__ $$aSana, H.
000002089 700__ $$aŠtefl, S.
000002089 700__ $$aZorec, J.
000002089 700__ $$aLacour, S.
000002089 700__ $$aLe Bouquin, J.-B.
000002089 700__ $$aMartins, F.
000002089 700__ $$aMérand, A.
000002089 700__ $$aPatru, F.
000002089 700__ $$aSelman, F.
000002089 700__ $$aFrémat, Y.
000002089 773__ $$cA115$$pAstronomy and Astrophysics$$v587$$y2016
000002089 85642 $$ahttp://esoads.eso.org/abs/2016A%26A...587A.115M
000002089 905__ $$apublished in
000002089 980__ $$aREFERD