The expanding fireball of Nova Delphini 2013
A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized […]
Overview of Stellar Interferometry and its contribution to the study of massive stars
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Improving the surface brightness-color relation for early-type stars using optical interferometry⋆
Context. The method of distance determination of eclipsing binaries consists in combining the radii of both components determined from spectro-photometric observations with their respective angular diameters derived from the surface brightness-color relation (SBC). However, the largest limitation of the method comes from the uncertainty on the SBC relation: about 2% for late-type stars (or 0.04 […]
An Overview of the MATISSE Instrument — Science, Concept and Current Status
MATISSE, a second generation Very Large Telescope Interferometer (VLTI) instrument, is a combined imager and spectrograph for interferometry in the 3-5 μm region (L- and M-bands) and the 8-13 μm window (N-band). MATISSE builds on the experience gained with the VLTI’s first generation instruments. It employs multi-axial beam combination while also providing wavelength differential visibility […]
Observation of Double Star by Long Baseline Interferometry
This paper serves as a reference on how to estimate the parameters of binary stars and how to combine multiple techniques, namely astrometry, interferometry and radial velocities.
Circumstellar disks
Disks are very common structures found around stars of different masses and evolutionary status. In this chapter we will discuss the basic properties of disks and how interferometric observations can put constraints on their structure. The chapter is organized in three sections: geometry of disks, physical conditions and chemical composition, and kinematics.
V838 Monocerotis: the central star and its environment a decade after outburst
<BR /> Aims: V838 Monocerotis erupted in 2002, brightened in a series of outbursts, and eventually developed a spectacular light echo. A very red star emerged a few months after the outburst. The whole event has been interpreted as the result of a merger. <BR /> Methods: We obtained near- and mid-IR interferometric observations of […]
Beyond the diffraction limit of optical/IR interferometers. II. Stellar parameters of rotating stars from differential phases
Context. As previously demonstrated on Achernar, one can derive the angular radius, rotational velocity, axis tilt, and orientation of a fast-rotating star from the differential phases obtained by spectrally resolved long baseline interferometry using earth-rotation synthesis. <BR /> Aims: We applied this method on a small sample of stars for different spectral types and classes, […]
Long baseline interferometry in the visible: the FRIEND project
In the next 2 or 3 years, the two major interferometric arrays, VLTI and CHARA, will equip their telescopes of 1.8m and 1m respectively with Adaptive Optics (AO hereafter) systems. This improvement will permit to apply with a reasonable e_ciency in the visible domain, the principle of spatial filtering with single mode fibers demonstrated in […]
MATISSE status report and science forecast
MATISSE is the mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This second generation interferometry instrument will open new avenues in the exploration of our Universe. Mid-infrared interferometry with MATISSE will allow significant advances in various fundamental research fields: studies of disks around young stellar objects where planets form and […]