| PSR B1259-63 | HESS J0632+057 | LS I +61 303 | LS 5039 | 1FGL J1018.6-5856 | |
|---|---|---|---|---|---|
| Compact | pulsar | ? | ? | ? | ? |
| Component | Be | Be | Be | O | O |
| $P_{orb}$(d) | 1236.7 | 315 | 26.5 | 3.9 | 16.6 |
Orbital geometry of LS I +61 303, looking down on the orbital plane, showing the relative orbits (r/a) of the optical star (12.5 M; Casares et al. 2005) and its compact companion of unknown mass. The relative orbit of the compact object is shown as a solid line, while the Be star’s relative orbit depends greatly on the mass of the companion. The dashed line indicates the Be star’s orbit assuming a 4 $M_{sun}$ black hole, while the dotted line assumes a 1.4 $M_{sun}$ neutron star. The relevant phases of periastron, apastron, and conjunctions are marked along the orbit of the compact companion. The center of mass is indicated with a cross, and the thin solid line is the orbital major axis.
Orbital geometry of LS 5039, looking down upon the orbital plane, in a similar format to upper figure. Here, the optical star (23 $M_{sun}$; Casares et al. 2005) orbits either a 3.7 $M_{sun}$ black hole (Casares et al. 2005b) or a 1.4 $M_{sun}$ neutron star.