LS 5039 system as determined by Casares et al. (2005) with an orbital period of P_orb = 3.9 d and an eccentricity of e = 0.35, assuming a stellar mass M_star = 23 M_⊙ and a pulsar mass M_pulsar = 1.4 M_⊙. Periastron, apastron, and the conjunctions are indicated. Matching the choices in Aharonian et al. (2006), the orbit is divided into two parts: INFC, ranging from 0.45 < ϕ < 0.9, and SUPC, for 0.9 < ϕ < 1 and 0 < ϕ < 0.45. We point out that, throughout the paper, the acronyms SUPC and INFC refer to the specified parts of the orbit, whereas the terms superior and inferior conjunction denote specific points on the orbit.