Related papers: Multi-wavelength interferometry of evolved stars u…
We give an introduction to interferometrical concepts and their applicability to Be stars. The first part of the paper concentrates on a short historic overview and basic principles of two-beam interferometric observations. In the second…
We measured the mid-infrared extension of the gaseous disk surrounding seven Be stars in order to constrain the geometry of their circumstellar environments and to try to infer physical parameters characterizing these disks. We used the…
The young eruptive star V1647 Ori was observed with MIDI, the mid-infrared interferometric instrument at the Very Large Telescope Interferometer (VLTI), on March 2, 2005. We present the first spectrally resolved interferometric visibility…
The late evolutionary stages of stellar evolution are a key ingredient for our understanding in many fields of astrophysics, including stellar evolution and the enrichment of the interstellar medium (ISM) via stellar yields. Already the…
SiO maser emission occurs in the extended atmosphere of evolved stars and can be studied at high angular resolution. Very long baseline interferometry (VLBI) observations of Mira variables indicate that SiO masers are significantly linearly…
We present new measurements of the millimeter wavelength continuum emission from the long period variable Mira ($o$ Ceti) at frequencies of 46 GHz, 96 GHz, and 229 GHz ($\lambda$~7 mm, 3 mm, and 1 mm) based on observations obtained with the…
Information about the inner structure of young stellar objects is crucial for understanding how the central forming stars gain their mass. However, especially for observations of (usually further away) high-mass young stellar objects,…
We have quantified the potential capabilities of detecting local brightness asymmetries in circumstellar disks with the Very Large Telescope Interferometer (VLTI) in the mid-infrared wavelength range. The study is motivated by the need to…
In order to directly study the role of magnetic fields in the immediate vicinity of protostars, we use Very-Long-Baseline Interferometry (VLBI), aiming at the detection of non-thermal centimetric radio emission. This is technically the only…
Context. We study the atmosphere of the carbon-rich Mira RU Vir using the mid-infrared high spatial resolution interferometric observations from VLTI/MIDI. Aims. The aim of this work is to analyse the atmosphere of the carbon-rich Mira RU…
We present optical interferometric polarimetry measurements of the Mira-like variables R Car and RR Sco, using the Sydney University Stellar Interferometer. By making visibility measurements in two perpendicular polarisations, the…
We determine the physical parameters of the outer atmosphere of a sample of eight evolved stars, including the red supergiant {\alpha} Scorpii, the red giant branch stars {\alpha} Bootis and {\gamma} Crucis, the K giant {\lambda} Velorum,…
We present mid-infrared interferometric observations of the Herbig Ae star R CrA obtained with MIDI at the VLTI using several projected baselines in the UT2-UT3 configuration. The observations show resolved circumstellar emission in the…
We report on observations of circumstellar disks around young stars that have been obtained with the MIDI instrument, which is mounted on the VLT Interferometer and operates in the 10 micrometer atmospheric window. The maximum spatial…
We present K-band observations of five Mira stars with the IOTA interferometer. The interferograms were obtained with the FLUOR fiber optics beam combiner which provides high-accuracy visibility measurements in spite of time-variable…
OHANA is an interferometric snapshot survey of the gaseous circumstellar environments of hot stars, carried out by the VLTI group at the Paranal observatory. It aims to characterize the mass-loss dynamics (winds/disks) at unexplored spatial…
We present the methodology and some preliminary results of our study of the relationship between a Mira's pulsating photosphere and its surrounding molecular layer(s) throughout several pulsation cycles, based on spatially resolved data.…
Massive stars deeply influence their surroundings by their luminosity and the injection of kinetic energy. So far, they have mostly been studied with spatially unresolved observations, although evidence of geometrical complexity of their…
The results of a high-resolution interferometric campaign targeting the symbiotic long-period variable (LPV) R~Aqr are reported. With both near-infrared measurements on baselines out to 10m and mid-infrared data extending to 32m, we have…
We present near-infrared K-band interferometric measurements of the Mira star R Leonis obtained in April 2001 and January 2002 with the VLTI, the commissioning instrument VINCI, and the two test siderostats. These epochs correspond to…