TOI-733 b
Astrophysical Synthesis & Habitability Characterization
TOI-733 b is a confirmed super-earth exoplanet orbiting the star TOI-733, located approximately 245.3 light-years (75.21 parsecs) from the Solar System. First announced in 2023 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.037% across the stellar disk), this world measures 1.992 Earth radii and has a measured mass of 5.72 Earth 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 1.44 g⊕ (14.12 m/s²), and an escape velocity of 19 km/s.
In its orbital architecture around TOI-733, TOI-733 b completes one full revolution every 4.885 Earth days at a semi-major axis of 0.0618 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 137.6 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.046 (ranging from 0.059 AU at periapsis to 0.0646 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1056 K (+783°C / +1441°F) and receiving 207.10 S⊕ (~281,863 W/m²), TOI-733 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-733 is classified as a solar-type yellow star of spectral type G with an effective photospheric temperature of 5,585 K, a radius of 0.949 R☉, a mass of 0.956 M☉, an estimated bolometric luminosity of 0.786 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.4 Gyr and a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, TOI-733 shines at apparent V-band magnitude 9.44 (accessible to binoculars and small amateur telescopes) in the Southern 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-733 |
| Spectral Type | G |
| Effective Temp (Teff) | 5,585 K |
| Stellar Radius | 0.9490 R☉ |
| Stellar Mass | 0.9560 M☉ |
| Bolometric Luminosity | 0.786 L☉ |
| Metallicity [Fe/H] | -0.040 dex |
| Stellar Age | 4.400 Gyr |
| Apparent Magnitude | V: 9.440 · G: 9.289 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.061800 AU |
| Orbital Period | 4.885 days |
| Mean Orbital Velocity | 137.6 km/s |
| Orbital Eccentricity (e) | 0.04600 |
| Orbital Inclination (i) | 88.8500° |
| Mean Bulk Density | 3.99 g/cm³ (19 km/s vesc) |
| Insolation Flux | 207.1000 S⊕ (~281,863 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 245.300 LY (75.209 pc) |