TOI-1288 b
Astrophysical Synthesis & Habitability Characterization
TOI-1288 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1288, located approximately 374.6 light-years (114.87 parsecs) from the Solar System. First announced in 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.2259% across the stellar disk), this world measures 4.968 Earth radii (0.44 Jupiter radii) and has a measured mass of 44.1 Earth masses (0.14 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.98 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.79 g⊕ (17.55 m/s²), and an escape velocity of 33.3 km/s.
In its orbital architecture around TOI-1288, TOI-1288 b completes one full revolution every 2.7 Earth days at a semi-major axis of 0.0374 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 150.7 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 1203 K (+930°C / +1706°F) and receiving 1,198.41 S⊕ (~1,631,036 W/m²), TOI-1288 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1288 is classified as a solar-type yellow star of spectral type G V with an effective photospheric temperature of 5,388 K, a radius of 0.9583 R☉, a mass of 0.9552 M☉, an estimated bolometric luminosity of 0.694 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.5 Gyr and a metallicity of [Fe/H] = 0.257 dex (metal-rich relative to the Sun). From Earth, TOI-1288 shines at apparent V-band magnitude 10.445 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1288 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-1288 b sharing its stellar neighborhood alongside TOI-1288 c.
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-1288 |
| Spectral Type | G V |
| Effective Temp (Teff) | 5,388 K |
| Stellar Radius | 0.9583 R☉ |
| Stellar Mass | 0.9552 M☉ |
| Bolometric Luminosity | 0.694 L☉ |
| Metallicity [Fe/H] | 0.257 dex |
| Stellar Age | 6.500 Gyr |
| Apparent Magnitude | V: 10.445 · G: 10.447 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.037400 AU |
| Orbital Period | 2.7 days |
| Mean Orbital Velocity | 150.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.5000° |
| Mean Bulk Density | 1.98 g/cm³ (33.3 km/s vesc) |
| Insolation Flux | 1198.4100 S⊕ (~1,631,036 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 374.600 LY (114.865 pc) |