7 CMa c
Astrophysical Synthesis & Habitability Characterization
7 CMa c 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 2019 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.9 Earth radii (1.24 Jupiter radii) and has a measured mass of 276.512 Earth masses (0.87 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.57 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.43 g⊕ (14.02 m/s²), and an escape velocity of 49.9 km/s.
In its orbital architecture around 7 CMa, 7 CMa c completes one full revolution every 996 Earth days (2.73Julian years) at a semi-major axis of 2.153 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 23.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.08 carries the world between 1.9808 AU at periapsis and 2.3252 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.900 R⊕, 7 CMa c exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
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 c sharing its stellar neighborhood alongside 7 CMa b.
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: Multiple Observatories · 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) | 2.153000 AU |
| Orbital Period | 996 days |
| Mean Orbital Velocity | 23.5 km/s |
| Orbital Eccentricity (e) | 0.08000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 0.57 g/cm³ (49.9 km/s vesc) |
| Insolation Flux | 2.4917 S⊕ (~3,391 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 64.600 LY (19.810 pc) |