A photometric study of the massive binary RY Sct ^*

¹ Astronomical Observatory, Volgina 7, 11050 Belgrade, Yugoslavia
² Astronomical Institute of Uzbek Academy of Sciences, Astronomicheskaya 33, 700052 Tashkent, Uzbekistan and Isaac Newton Institute of Chili, Uzbek branch
³ Astronomical Institute of Uzbek Academy of Sciences, Astronomicheskaya 33, 700052 Tashkent, Uzbekistan

Corresponding author: G. Djurasević, gdjurasevic@aob.bg.ac.yu

Received: 14 April 2000
Accepted: 17 May 2001

Abstract

The present study deals with the problem of the estimation of the orbital and physical parameters for the EB-type eclipsing binary RY Sct, based on the interpretation of new photometric U B V R observations. The light curves obtained at the Maidanak Observatory during 1979-94 show a slight asymmetry around the secondary minima and a small difference in the height of the successive maxima. The light curves are analysed in the framework of the Roche computer model (Djurašević [CITE]) by applying the inverse-problem method (Djurašević [CITE]) based on Marquardt's ([CITE]) algorithm. The analysis shows that RY Sct system is in an overcontact configuration with and , generating total-annular eclipses. The basic parameters of the system and of the active region are estimated for all individual U, B, V and R light curves. Our results suggested a mass exchange between the components and mass loss through the outer Lagrangian point L₃. This could be taken as a possible mechanism in the formation of the circumstellar envelope of toroidal form lying in the orbital plane of the system.