Research Note

The orbital modulation of the X-ray binary V Sagittae in the high and low states

¹ Astronomical Institute, Academy of Sciences of the Czech Republic, 251 65 Ondřejov, Czech Republic
² Astronomical Institute of the Slovak Academy of Sciences, 059 60 Tatranská Lomnica, Slovakia
³ Department of Mathematics, Informatics and Physics, Faculty of Education, University of Trnava, 918 43 Trnava, Slovakia
⁴ Hlohovec Observatory, Sládkovičova 41, 920 01 Hlohovec, Slovakia
⁵ Sternberg Astronomical Institute, Moscow State University, Universitetsky Prospect 13, 119899 Moscow, Russia
⁶ Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, 157 84 Zografos, Athens, Greece
⁷ Department of Astronomy, Odessa State University, T.G. Shevchenko park, 65014 Odessa, Ukraine

Corresponding author: V. Šimon, simon@asu.cas.cz

Received: 5 February 2002
Accepted: 3 July 2002

Abstract

Our analysis of the orbital modulation of V Sge, carried out in the intensity scale instead of the previously used magnitude scale, revealed that the full amplitude of the modulation remains almost constant as the intensity of the system rises from the low to the high state. The primary minimum remains very similar, as regards both its depth and width. The secondary minimum tends to slightly lag behind phase 0.5. The depth of the secondary minimum is subjected to the largest changes; it becomes almost as deep as the primary minimum during the high state while it is significantly more shallow than the primary one in the low state.