TOI-1798.01
Astrophysical Synthesis & Habitability Characterization
TOI-1798.01 is a confirmed sub-neptune exoplanet orbiting the star TOI-1798, located approximately 369.1 light-years (113.18 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 0.0828% across the stellar disk), this world measures 2.448 Earth radii and has a measured mass of 6.5 Earth masses. Combining its mass and radius yields a mean bulk density of 2.44 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 18.2 km/s.
In its orbital architecture around TOI-1798, TOI-1798.01 completes one full revolution every 8.022 Earth days at a semi-major axis of 0.074984 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 101.7 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 734 K (+461°C / +862°F) and receiving 69.26 S⊕ (~94,263 W/m²), TOI-1798.01 orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1798 is classified as a stellar host with an effective photospheric temperature of 5,165 K, a radius of 0.78 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.388 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.6 Gyr and a metallicity of [Fe/H] = 0.073 dex (metal-rich relative to the Sun). From Earth, TOI-1798 shines at apparent V-band magnitude 11.361 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1798 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-1798.01 sharing its stellar neighborhood alongside TOI-1798.02.
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-1798 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,165 K |
| Stellar Radius | 0.7800 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.388 L☉ |
| Metallicity [Fe/H] | 0.073 dex |
| Stellar Age | 2.600 Gyr |
| Apparent Magnitude | V: 11.361 · G: 11.067 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.074984 AU |
| Orbital Period | 8.022 days |
| Mean Orbital Velocity | 101.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.4352° |
| Mean Bulk Density | 2.44 g/cm³ (18.2 km/s vesc) |
| Insolation Flux | 69.2600 S⊕ (~94,263 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 369.100 LY (113.181 pc) |