| Object | Location | Companion Star | Orbital Period | Mass of Compact Object |
| Cygnus X-1 | Cygnus | O Supergiant | 5.6 days | 10-15 Solar masses |
| LMC X-3 | Dorado | B3 main-sequence | 1.7 days | 4-11 solar masses |
| V616 Mon | Monocerotis | K main-sequence | 7.75 hours | 3.3-4.2 solar masses |
| V404 Cygni | Cygnus | K main-sequence | 6.47 days | 8-15 solar masses |
| J1655-40 | Scorpius | F-G main-sequence | 2.61 days | 4-5.2 solar masses |
| QZ Vul | Vulpecula | K main-sequence | 8 hours | 5-14 solar masses |