TOI-5616 b
Astrophysical Synthesis & Habitability Characterization
TOI-5616 b is a confirmed gas giant exoplanet orbiting the star TOI-5616, located approximately 1273.4 light-years (390.42 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 2.3405% across the stellar disk), this world measures 10.78 Earth radii (0.96 Jupiter radii) and has a measured mass of 624 Earth masses (1.96 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.75 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 5.37 g⊕ (52.66 m/s²), and an escape velocity of 85.1 km/s.
In its orbital architecture around TOI-5616, TOI-5616 b completes one full revolution every 2.003 Earth days at a semi-major axis of 0.0272 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 147.7 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 939 K (+666°C / +1231°F) and receiving 137.00 S⊕ (~186,457 W/m²), TOI-5616 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5616 is classified as a stellar host with an effective photospheric temperature of 3,996 K, a radius of 0.646 R☉, a mass of 0.666 M☉, an estimated bolometric luminosity of 0.095 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.2 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, TOI-5616 shines at apparent V-band magnitude 16.74 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-5616 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,996 K |
| Stellar Radius | 0.6460 R☉ |
| Stellar Mass | 0.6660 M☉ |
| Bolometric Luminosity | 0.095 L☉ |
| Metallicity [Fe/H] | 0.140 dex |
| Stellar Age | 7.200 Gyr |
| Apparent Magnitude | V: 16.740 · G: 15.631 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.027200 AU |
| Orbital Period | 2.003 days |
| Mean Orbital Velocity | 147.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.1300° |
| Mean Bulk Density | 2.75 g/cm³ (85.1 km/s vesc) |
| Insolation Flux | 137.0000 S⊕ (~186,457 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1273.400 LY (390.415 pc) |