Related papers: MIDI interferometry of massive YSOs: Updates on th…
The mid-infrared provides a unique view of galaxy stellar populations, sensitive to both the integrated light of old, low-mass stars and to individual dusty mass-losing stars. We present results from an extended Spitzer/IRAC survey of M31…
Multi-epoch radio-interferometric observations of young stellar objects can be used to measure their displacement over the celestial sphere with a level of accuracy that currently cannot be attained at any other wavelength. In particular,…
Accretion in young stellar objects (YSOs) is at least partially episodic, i.e. periods with high accretion rates ('bursts') are interspersed by quiescent phases. These bursts manifest themselves as eruptive variability. Here we present a…
We report on our project of coordinated VLTI/VLBA observations of the atmospheres and circumstellar environments of evolved stars. We illustrate in general the potential of interferometric measurements to study stellar atmospheres and…
Recent studies have identified several young stellar objects (YSOs) which exhibit significant mid-infrared (mid-IR) variability. A wide range of physical mechanisms may be responsible for these variations, including changes in a YSO's…
Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying…
Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the Rho Ophiuchi cloud are presented. Data were acquired at the Palomar 5-m and at the Keck 10-m telescopes with the MIRLIN and LWS…
The dynamics of the inner regions of young stellar objects (YSOs) is driven by a variety of physical phenomena, from magnetospheres and accretion to the dust sublimation rim and inner disk flows. These inner environments evolve on…
So far, high resolution techniques on the one hand provide morphological information on bright nearby objects. On the other hand, telescopes with large collecting areas allow us to detect very faint and distant objects, but not to obtain a…
Most, if not all, stars are now believed to produce energetic outflows during their formation. Yet, almost 20 years after the discovery of bipolar outflows from young stars, the origins of this violent phenomenon are not well understood.…
Detailed radial/vertical structure modeling of observations of disks around Young Stellar Objects (YSOs) can provide information on the physical conditions and on the characteristics of the gas and dust in their interiors. We describe…
Diffuse emission in the mid-infrared shows a wealth of structure, that lends itself to high-resolution structure analysis of the interstellar gas. A large part of the emission comes from polycyclic aromatic hydrocarbons, excited by nearby…
We summarize the main results of a mid-IR photometric survey with ISO for a few nearby embedded clusters. The sensitivity and spatial resolution of ISOCAM provided a wonderful tool for studies of the youngest stellar clusters, which are…
We have observed Centaurus A with the MID-infrared Interferometric instrument (MIDI) at the Very Large Telescope Interferometer (VLTI) at resolutions of 7 - 15 mas (at 12.5 micron) and filled gaps in the (u,v) coverage in comparison to…
The optically invisible infrared-source NGC 2264 IRS 1 is thought to be a massive young stellar object (~10 Msun). Although strong infrared excess clearly shows that the central object is surrounded by large amounts of circumstellar…
The luminous Young Stellar Object (YSO) IRAS 07422-2001 is studied in the infrared. We discover star forming activity in embedded clusters located in a cloud detected at mid-IR wavelengths in emission. Multiple outflows are discovered from…
Studying the physical conditions structuring the young circumstellar disks is required for understanding the onset of planet formation. Of particular interest is the protoplanetary disk surrounding the Herbig star MWC480. The structure and…
We investigate the possibility to find evidence for planets in circumstellar disks by infrared and submillimeter interferometry. Hydrodynamical simulations of a circumstellar disk around a solar-type star with an embedded planet of 1…
Current detection methods of planetary companions do not allow retrieving their spectral information properties. The method of Differential Interferometry has the potential to complement such information by comparing interferometric…
Context. A characteristic feature of young stellar objects is their variability, which is caused by a variety of different physical processes. High-resolution interferometric observations in the near- and mid-infrared wavelength ranges…