Optical CCD photometry of the microquasar LS 5039

¹ Departamento de Física, Escuela Politécnica Superior, Universidad de Jaén, Virgen de la Cabeza 2, 23071 Jaén, Spain e-mail: jlg@ujaen.es
² Departamento de Ingeniería Mecánica y Minera, Escuela Universitaria Politécnica de Linares, Universidad de Jaén, C/ Alfonso X el Sabio 28, 23700 Linares, Spain e-mail: peter@ujaen.es
³ Departament d'Astronomia i Meteorologia, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona, Spain e-mail: jmparedes@ub.edu
⁴ Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Birkenhead, CH41 1LD, UK e-mail: rz@astro.livjm.ac.uk

Corresponding author: J. Martí, jmarti@ujaen.es

Received: 16 December 2003
Accepted: 15 January 2004

Abstract

We report optical CCD observations of the microquasar LS 5039. Its photometric behaviour is studied over different orbital periods with a time separation of three years. We do not detect evidences of an ellipsoidal modulation above the mag level, thus confirming the previous results reported by Clark et al. ([CITE]). The light curve of LS 5039 has also been explored with a time resolution of 30 s but the source also appears to be stable on such shorter time scales. Possible scenarios consistent with the non-detection of optical variability are considered.