TOI-1823 b
Astrophysical Synthesis & Habitability Characterization
TOI-1823 b is a confirmed gas giant exoplanet orbiting the star TOI-1823, located approximately 233.7 light-years (71.65 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 0.7378% across the stellar disk), this world measures 7.541 Earth radii (0.67 Jupiter radii) and has a measured mass of 67.4 Earth masses (0.21 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.87 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 33.4 km/s.
In its orbital architecture around TOI-1823, TOI-1823 b completes one full revolution every 38.8 Earth days at a semi-major axis of 0.212 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 59.4 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 424 K (+151°C / +304°F) and receiving 9.30 S⊕ (~12,653 W/m²), TOI-1823 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1823 is classified as a stellar host with an effective photospheric temperature of 4,927 K, a radius of 0.8049 R☉, a mass of 0.8414 M☉, an estimated bolometric luminosity of 0.343 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.3 Gyr and a metallicity of [Fe/H] = 0.243 dex (metal-rich relative to the Sun). From Earth, TOI-1823 shines at apparent V-band magnitude 10.728 (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-1823 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,927 K |
| Stellar Radius | 0.8049 R☉ |
| Stellar Mass | 0.8414 M☉ |
| Bolometric Luminosity | 0.343 L☉ |
| Metallicity [Fe/H] | 0.243 dex |
| Stellar Age | 6.300 Gyr |
| Apparent Magnitude | V: 10.728 · G: 10.391 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.212000 AU |
| Orbital Period | 38.8 days |
| Mean Orbital Velocity | 59.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.87 g/cm³ (33.4 km/s vesc) |
| Insolation Flux | 9.2972 S⊕ (~12,653 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 233.700 LY (71.646 pc) |