TIC 139270665 c
Astrophysical Synthesis & Habitability Characterization
TIC 139270665 c is a confirmed gas giant exoplanet orbiting the star TIC 139270665, located approximately 619.3 light-years (189.88 parsecs) from the Solar System. First announced in 2024 by Lick Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.9 Earth radii (1.15 Jupiter radii) and has a measured mass of 1554.181 Earth masses (4.89 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.99 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 9.34 g⊕ (91.59 m/s²), and an escape velocity of 122.8 km/s.
In its orbital architecture around TIC 139270665, TIC 139270665 c completes one full revolution every 1010 Earth days (2.77Julian years) at a semi-major axis of 2 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 21.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.566, swinging from 0.868 AU at periapsis out to 3.132 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.900 R⊕, TIC 139270665 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 TIC 139270665 is classified as a solar-type yellow star of spectral type G2 with an effective photospheric temperature of 5,844 K, a radius of 1.016 R☉, a mass of 1.035 M☉, an estimated bolometric luminosity of 1.08 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.4 Gyr and a metallicity of [Fe/H] = 0.156 dex (metal-rich relative to the Sun). From Earth, TIC 139270665 shines at apparent V-band magnitude 10.385 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TIC 139270665 system is a multi-planet architecture hosting 2 confirmed worlds, with TIC 139270665 c sharing its stellar neighborhood alongside TIC 139270665 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: Lick Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TIC 139270665 |
| Spectral Type | G2 |
| Effective Temp (Teff) | 5,844 K |
| Stellar Radius | 1.0160 R☉ |
| Stellar Mass | 1.0350 M☉ |
| Bolometric Luminosity | 1.08 L☉ |
| Metallicity [Fe/H] | 0.156 dex |
| Stellar Age | 3.400 Gyr |
| Apparent Magnitude | V: 10.385 · G: 10.181 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.000000 AU |
| Orbital Period | 1010 days |
| Mean Orbital Velocity | 21.5 km/s |
| Orbital Eccentricity (e) | 0.56600 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 3.99 g/cm³ (122.8 km/s vesc) |
| Insolation Flux | 0.2100 S⊕ (~286 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 619.300 LY (189.875 pc) |