Title:
Aperture Synthesis with the IOTA Interferometer plus Keck-I Aperture Masking
Authors:
Monnier, J. D.; Millan-Gabet, R.; Tuthill, P. G.; Traub, W.; Carleton, N.; Coude du Foresto, V.; Danchi, W. C.; Lacasse, M.; Morel, S.; Perrin, G.; Porro, I.
Affiliation:
AB(Harvard-Smithsonian Center for Astrophysics), AC(University of Sydney), AE(Harvard-Smithsonian Center for Astrophysics), AF(Observatoire de Paris-Meudon), AG(NASA Goddard Space Flight Center), AI(Harvard-Smithsonian Center for Astrophysics), AJ(Observatoire de Paris-Meudon), AK(Harvard-Smithsonian Center for Astrophysics)
Journal:
American Astronomical Society Meeting 198, #63.02
Publication Date:
05/2001
Origin:
AAS
Abstract Copyright:
(c) 2001: American Astronomical Society
Bibliographic Code:
2001AAS...198.6302M

Abstract

Coordinated observations with the IOTA interferometer and Keck-I aperture masking have allowed aperture synthesis "imaging" of evolved stars with an equivalent aperture of up to 38 meters at 2.2 microns. The diameters of many "famous" evolved star prototypes (e.g., VY CMa, NML Cyg, IK Tau, VX Sgr) have never been measured because of difficulties associated with dust obscuration in the visible and dust emission in the infrared. We present preliminary results of decomposing the dust and stellar signatures from these sources using contemporaneous observations (within a few weeks) at Mt. Hopkins and Mauna Kea. In addition, the photospheres of a few bright Miras and supergiants have been observed, with extensive (Keck) sampling before the first null of the 2-D visibility and IOTA measurements beyond, allowing detection of surface structures/elongations (if present) and determination of limb darkening at 2.2 microns.