V 700 Cygni and AW Virginis: Two W-type W UMa systems with spotted components^*

¹ Section of Astrophysics, Department of Physics, University of Athens, Panepistimiopolis, GR-15784 Zografos, Athens, Greece
² Alter Weg 7, D-54570 Weidenbach, Germany
³ European Southern Observatory, Casilla 19001, Santiago 19, Chile
⁴ Astronomisches Institut, Wilhelm-Klemm-Str. 10, D-48149 Münster, Germany

Send offprint request to: P.G. Niarchos

Received: 10 April 1996
Accepted: 18 November 1996

Abstract

A photometric analysis of the W UMa systems V 700 Cyg and AW Vir, based on photoelectric B and V light curves, is presented. Since no spectroscopic mass-ratio is available, the q-search method was applied to find the preliminary range of the mass-ratio in order to search for the final solution. First, an unspotted solution was carried out by using the unperturbed parts of the light curves and applying the DC program of the WD code. The final spotted solution was made by adopting spot models for the two systems. In the case of V 700 Cyg, two cool spots were placed on the primary (more massive, larger and cooler) component to explain the O'Connell effect ( fainter than ) and a small deficit of light just before . In the case of AW Vir, one cool spot was placed on the primary component to explain the relatively large O'Connell effect. Both objects are W-type systems with partial eclipses; V 700 Cyg is fairly evolved while AW Vir is rather unevolved.