7 CMa b
Astrophysical Synthesis & Habitability Characterization
7 CMa b is a confirmed gas giant exoplanet orbiting the star 7 CMa, located approximately 64.6 light-years (19.81 parsecs) from the Solar System. First announced in 2011 by Anglo-Australian Telescope using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.4 Earth radii (1.2 Jupiter radii) and has a measured mass of 587.986 Earth masses (1.85 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.35 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.27 g⊕ (32.07 m/s²), and an escape velocity of 74.1 km/s.
In its orbital architecture around 7 CMa, 7 CMa b completes one full revolution every 735.1 Earth days (2.01Julian years) at a semi-major axis of 1.758 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 26 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.06 carries the world between 1.6525 AU at periapsis and 1.8635 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 387 K (+114°C / +237°F) and receiving 3.74 S⊕ (~5,086 W/m²), 7 CMa b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star 7 CMa is classified as an orange K-type star of spectral type K1III(+M) with an effective photospheric temperature of 4,826 K, a radius of 4.87 R☉, a mass of 1.34 M☉, an estimated bolometric luminosity of 11.542 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.3 Gyr and a metallicity of [Fe/H] = 0.21 dex (metal-rich relative to the Sun). From Earth, 7 CMa shines at apparent V-band magnitude 3.95 (visible to the unaided human eye under dark skies) in the Southern celestial hemisphere. The 7 CMa system is a multi-planet architecture hosting 2 confirmed worlds, with 7 CMa b sharing its stellar neighborhood alongside 7 CMa c.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Anglo-Australian Telescope · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | 7 CMa |
| Spectral Type | K1III(+M) |
| Effective Temp (Teff) | 4,826 K |
| Stellar Radius | 4.8700 R☉ |
| Stellar Mass | 1.3400 M☉ |
| Bolometric Luminosity | 11.542 L☉ |
| Metallicity [Fe/H] | 0.210 dex |
| Stellar Age | 4.300 Gyr |
| Apparent Magnitude | V: 3.950 · G: 3.679 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.758000 AU |
| Orbital Period | 735.1 days |
| Mean Orbital Velocity | 26 km/s |
| Orbital Eccentricity (e) | 0.06000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 1.35 g/cm³ (74.1 km/s vesc) |
| Insolation Flux | 3.7372 S⊕ (~5,086 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 64.600 LY (19.810 pc) |