TOI-4499 b
Astrophysical Synthesis & Habitability Characterization
TOI-4499 b is a confirmed sub-neptune exoplanet orbiting the star TOI-4499, located approximately 573.2 light-years (175.74 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0325% across the stellar disk), this world measures 2.14 Earth radii and has a measured mass of 5.22 Earth masses. Combining its mass and radius yields a mean bulk density of 2.94 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.14 g⊕ (11.18 m/s²), and an escape velocity of 17.5 km/s.
In its orbital architecture around TOI-4499, TOI-4499 b completes one full revolution every 5.539 Earth days. 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 1352 K (+1079°C / +1974°F) and receiving 555.87 S⊕ (~756,543 W/m²), TOI-4499 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4499 is classified as a stellar host with an effective photospheric temperature of 6,111 K, a radius of 1.0889 R☉, a mass of 1.151 M☉, an estimated bolometric luminosity of 1.484 L☉. From Earth, TOI-4499 shines at apparent V-band magnitude 10.61 (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-4499 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,111 K |
| Stellar Radius | 1.0889 R☉ |
| Stellar Mass | 1.1510 M☉ |
| Bolometric Luminosity | 1.484 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 10.610 · G: 10.525 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 5.539 days |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.94 g/cm³ (17.5 km/s vesc) |
| Insolation Flux | 555.8730 S⊕ (~756,543 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 573.200 LY (175.743 pc) |