Publications
of the
MPIfR Optical & Infrared Interferometry Group

K. Ohnaka, U. Beckmann, K.-H. Hofmann, V. Malanushenko, D. Schertl, G. Weigelt, A. Ahearn, J.-P. Berger, M. Lacasse, R. Millan-Gabet, J. Monnier, W. Traub, M. Brewer, P. Schloerb, V. Shenavrin, B. Yudin

IOTA observations of the circumstellar envelope of R CrB

Astronomische Gesellschaft Abstract Series (AGM 19, P36)
Der kosmische Materiekreislauf
Annual Scientific Meeting of the Astronomische Gesellschaft, Sep 23-28, 2002, Berlin, Germany

Abstract

We report the first long baseline interferometric observation of R CrB at maximum light. The observation was carried out at Infrared Optical Telescope Array (IOTA), using our beam combiner which enables us to record fringes simultaneously in the J-, H-, and K'-bands. The circumstellar envelope of R CrB is resolved with a baseline of 21 m, and the visibility at the K-band is derived to be 0.6. The new visibility obtained with IOTA and spectral energy distribution are fitted with 2-component models consisting of the central star and an optically thin dust shell. The predicted visibilities in the K-band tend to be by ~10% smaller than the observed. However, given the simplifications adopted in our models and the complex nature of the object, this can be regarded as rough agreement. As an alternative explaination for this small discrepancy, we propose that there might be a group of newly formed dust clouds close to the central star.