High angular resolution observations in the near infrared and modeling of the peculiar envelope of HD 62623

¹ Observatoire Midi-Pyrénées, CNRS UMR 5572, 14 Av. Edouard Belin, 31400 Toulouse, France
² Chatterton Astronomy Departement, School of Physics, University of Sydney, NSW 2006, Australia
³ Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
⁴ Observatoire de la Côte d'Azur, Département Fresnel UMR 6528, BP 4229, 06034 Nice Cedex 4, France
⁵ NASA Goddard Space Flight Center, Infrared Astrophysics Branch, Code 685, Greenbelt, MD 207741, USA
⁶ Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720-7450, USA
⁷ Observatoire de la Côte d'Azur, Département Fresnel UMR 6528, Caussols, 06460 St. Vallier de Thiey, France

Corresponding author: J. Bittar, bittar@obs-mip.fr

Received: 20 June 2000
Accepted: 19 December 2000

Abstract

We report new observations of the peculiar star HD 62623 obtained with aperture masking interferometry performed on the Keck I telescope at λ = 1.24, 1.65, 2.26 and 3.08 . The envelope around this star appears partially resolved in the near infrared except at 1.65 . Radiative transfer modeling of the dust shell of this star has been performed in spherical geometry. This modeling has two goals: it provides a framework for understanding the partially resolved object shown by the visibility curves, and it allows investigation of the envelope of HD 62623 by discrimination between proposed models. We show that reasonable fits to photometric observations can be obtained with a simple spherically symmetric silicate dust shell. Nevertheless, our high angular resolution measurements bring some important constraints on the modeling of the circumstellar environment of HD 62623. More realistic model involving the presence of a non spherically distributed dust envelope including the gas component in the circumstellar environment is required.