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Observations of Mira stars with the IOTA/FLUOR interferometer and comparison with Mira star models

✍ Scribed by K.-H. Hofmann; U. Beckmann; T. Blöcker; V.Coudé du Foresto; M. Lacasse; B. Mennesson; R. Millan-Gabet; S. Morel; G. Perrin; B. Pras; C. Ruilier; D. Schertl; M. Schöller; M. Scholz; V. Shenavrin; W. Traub; G. Weigelt; M. Wittkowski; B. Yudin


Publisher
Elsevier Science
Year
2002
Tongue
English
Weight
259 KB
Volume
7
Category
Article
ISSN
1384-1076

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✦ Synopsis


We present K9-band observations of five Mira stars with the IOTA interferometer. The interferograms were obtained with the FLUOR fiber optics beam combiner, which provides high-accuracy visibility measurements in spite of time-variable atmospheric conditions. For the M-type Miras X Oph, R Aql, RU Her, R Ser, and the C-type Mira V CrB we derived the uniform-disk diameters 11.7 mas, 10.9 mas, 8.4 mas, 8.1 mas, and 7.9 mas (60.3 mas), respectively. Simultaneous photometric observations yielded the bolometric fluxes. The derived angular Rosseland radii and the bolometric fluxes allowed the determination of effective temperatures. For instance, the effective temperature of R Aql was determined to be 1100 2970 6110 K. A linear Rosseland radius for R Aql of 250 R was derived from the angular Rosseland radius of 260 ( 5.560.2 mas and the HIPPARCOS parallax of 4.7361.19 mas. The observations were compared with theoretical Mira star models of Bessel et al. [A&A 307 (1996) 481] and Hofmann et al. [A&A 339 (1998) 846]. The effective temperatures of the M-type Miras and the linear radius of R Aql indicate fundamental mode pulsation.