Issue |
EAS Publications Series
Volume 6, 2003
Observing with the VLTI
|
|
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Page(s) | 253 - 253 | |
DOI | https://doi.org/10.1051/eas:2003023 | |
Published online | 31 January 2003 |
G. Perrin and F. Malbet (eds)
EAS Publications Series, 6 (2003) 253
VLTI/MIDI observations of the circumstellar shell of an AGB star: W Hydrae
1
Institute of Astronomy, University of
Cambridge, Madingley Road, Cambridge CB3 0HA, UK
2
Harvard-Smithsonian Center for
Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
3
Universidad de Concepción,
Departamento de Física, Casilla 160-C, Concepción, Chile; Warsaw
University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
W Hydrae is a prototype AGB star with a dusty circumstellar shell. The shell is marginally resolved at ground-based sub-arcsecond resolution; the unresolved dust condensation radius is expected to be of order 30-50 mas. Since the dusty circumstellar shell is brightest in the mid-IR, the high spatial resolution required at mid-infrared wavelengths can currently only be achieved by using MIDI on the VLTI. We therefore outline a possible observing programme for the VLTI, using MIDI at 10 μm. In a single night of short-baseline VLTI observations with two Auxiliary Telescopes, we can achieve sufficient (u,v) plane coverage to resolve the shell geometry of W Hya, which will provide strong constraints on the mass loss processes in late-type stars. We expect to either obtain an estimate of the dust condensation temperature, or evidence for interrupted mass loss.
© EAS, EDP Sciences, 2003