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VLTI/AMBER spectro-interferometry of the Herbig Be star MWC 297 with spectral resolution 12 000

Context. Circumstellar disks and outflows play a fundamental role in star formation. Infrared spectro-interferometry allows the inner accretion-ejection region to be resolved. <BR /> Aims: We study the disk and Brγ-emitting region of <ASTROBJ>MWC 297</ASTROBJ> with high spatial and spectral resolution and compare our observations with disk-wind models. <BR /> Methods: We measured interferometric visibilities, […]

Imaging the spinning gas and dust in the disc around the supergiant A[e] star HD 62623

Context. To progress in the understanding of evolution of massive stars one needs to constrain the mass-loss and determine the phenomenon responsible for the ejection of matter an its reorganization in the circumstellar environment <BR /> Aims: In order to test various mass-ejection processes, we probed the geometry and kinematics of the dust and gas […]

Time, spatial, and spectral resolution of the Hα line-formation region of Deneb and Rigel with the VEGA/CHARA interferometer

Context. BA-type supergiants are amongst the most optically-bright stars. They are observable in extragalactic environments, hence potential accurate distance indicators. <BR /> Aims: An extensive record of emission activity in the Hα line of the BA supergiants β Orionis (Rigel, B8Ia) and α Cygni (Deneb, A2Ia) is indicative of localized time-dependent mass ejections. However, little […]

First results from VLTI near-infrared interferometry on high-mass young stellar objects

Due to the recent dramatic technological advances, infrared interferometry can now be applied to new classes of objects, resulting in exciting new science prospects, for instance, in the area of high-mass star formation. Although extensively studied at various wavelengths, the process through which massive stars form is still only poorly understood. For instance, it has […]

A hot compact dust disk around a massive young stellar object

Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which strong radiation pressure might halt mass infall. Massive stars may form by stellar merging, although more recent theoretical […]

Revealing the sub-AU asymmetries of the inner dust rim in the disk around the Herbig Ae star R Coronae Austrinae

Context: Unveiling the structure of the disks around intermediate-mass pre-main-sequence stars (Herbig Ae/Be stars) is essential for our understanding of the star and planet formation process. In particular, models predict that in the innermost AU around the star, the dust disk forms a “puffed-up” inner rim, which should result in a strongly asymmetric brightness distribution […]

The galactic unclassified B[e] star HD 50138. I. A possible new shell phase

Context: The observed spectral variation of HD 50138 has led different authors to classify it in a very wide range of spectral types and luminosity classes (from B5 to A0 and III to Ia) and at different evolutionary stages as either HAeBe star or classical Be.<BR /> Aims: Based on new high-resolution optical spectroscopic data […]

B[e] stars at the highest angular resolution: the case of HD87643

New results on the B[e] star HD87643 are presented here. They were <P />obtained with a wide range of different instruments, from wide-field <P />imaging with the WFI camera, high resolution spectroscopy with the <P />FEROS instrument, high angular resolution imaging with the adaptive <P />optics camera NACO, to the highest angular resolution available with […]