VizieR Online Data Catalog: β Lyr light curves (Mourard+, 2018)
Our study is based on the following sets of dedicated spectrointerferometric observations and multicolor photometric observations. <P />Three spectro-interferometric instruments took part in a twelve nights long observational campaign aimed at β Lyr in 2013. We also have at our disposal all previous interferometric observations as detailed below. <P />Navy Precision Optical Interferometer (NPOI) (Armstrong […]
The installation and ongoing commissioning of the MATISSE mid-infrared interferometer at the ESO Very Large Telescope Observatory
MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments […]
MATISSE: performance in laboratory, results of AIV in Paranal, and first results on sky
MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) is the spectro-interferometer for the VLTI of the European Southern Observatory (ESO), operating in the L-, M- and N- spectral bands, and combining up to four beams from the unit or the auxiliary telescopes (UTs or ATs). MATISSE will offer new breakthroughs in the study of circumstellar environments by […]
Commissioning MATISSE: first results
MATISSE is the 2<SUP>nd</SUP> generation mid-infrared instrument designed to combine four VLTI telescopes in the L, M and N spectral bands. It’s commissioning in Paranal is in progress since March 2018 and should continue until the middle of 2019. Here we report, in June 2018, the commissioning plan, tools and the preliminary results of the […]
Multi-epoch VLTI-PIONIER imaging of the supergiant V766 Cen
Context. The star V766 Cen (=HR 5171A) was originally classified as a yellow hypergiant but lately found to more likely be a 27-36 M<SUB>☉</SUB> red supergiant (RSG). Recent observations indicated a close eclipsing companion in the contact or common-envelope phase. <BR /> Aims: Here, we aim at imaging observations of V766 Cen to confirm the […]
Flattening and surface-brightness of the fast-rotating star δ Persei with the visible VEGA/CHARA interferometer
Context. Rapid rotation is a common feature for massive stars, with important consequences on their physical structure, flux distribution and evolution. Fast-rotating stars are flattened and show gravity darkening (non-uniform surface intensity distribution). Another important and less studied impact of fast-rotation in early-type stars is its influence on the surface brightness colour relation (hereafter SBCR), […]
Science cases for a visible interferometer
High spatial resolution is the key for the understanding various astrophysical phenomena. But even with the future E-ELT, single dish instruments are limited to a spatial resolution of about 4 mas in the visible. For the closest objects within our Galaxy most of the stellar photosphere remains smaller than 1 mas. With the success of […]
Probing Gas and Dust around B[e] Stars at the Highest Angular Resolution: A Decade of Interferometric Studies
Long-baseline interferometry is the one and only technique offering the sub-milliarcsecond resolution needed to spatially resolve the close environment of stars. Since the construction of modern facilities such as the Very Large Telescope Interferometer (VLTI) in Chile, and the Center for High Resolution Array (CHARA) in California, it became a key technique to probe massive […]
VEGA/CHARA interferometric observations of Cepheids. I. A resolved structure around the prototype classical Cepheid δ Cep in the visible spectral range
Context. The B-W method is used to determine the distance of Cepheids and consists in combining the angular size variations of the star, as derived from infrared surface-brightness relations or interferometry, with its linear size variation, as deduced from visible spectroscopy using the projection factor. The underlying assumption is that the photospheres probed in the […]
Grown-up stars physics with MATISSE
MATISSE represents a great opportunity to image the environment around massive and evolved stars. This will allow one to put constraints on the circumstellar structure, on the mass ejection of dust and its reorganization, and on the dust-nature and formation processes. MATISSE measurements will often be pivotal for the understanding of large multiwavelength datasets on […]