TOI-2977 b
Astrophysical Synthesis & Habitability Characterization
TOI-2977 b is a confirmed gas giant exoplanet orbiting the star TOI-2977. First announced in 2023 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 1.2641% across the stellar disk), this world measures 13.159 Earth radii (1.17 Jupiter radii) and has a measured mass of 533.952 Earth masses (1.68 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.29 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.08 g⊕ (30.2 m/s²), and an escape velocity of 71.3 km/s.
In its orbital architecture around TOI-2977, TOI-2977 b completes one full revolution every 2.351 Earth days at a semi-major axis of 0.03386 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 156.7 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 1544 K (+1271°C / +2320°F) and receiving 947.80 S⊕ (~1,289,956 W/m²), TOI-2977 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2977 is classified as a stellar host with an effective photospheric temperature of 5,691 K, a radius of 1.073 R☉, a mass of 0.936 M☉, an estimated bolometric luminosity of 1.084 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.8 Gyr and a metallicity of [Fe/H] = 0.013 dex (near-solar heavy-element abundance). From Earth, TOI-2977 shines at apparent V-band magnitude 12.633 (faint and requiring research-grade or CCD telescopic photometry) 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-2977 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,691 K |
| Stellar Radius | 1.0730 R☉ |
| Stellar Mass | 0.9360 M☉ |
| Bolometric Luminosity | 1.084 L☉ |
| Metallicity [Fe/H] | 0.013 dex |
| Stellar Age | 9.800 Gyr |
| Apparent Magnitude | V: 12.633 · G: 12.444 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.033860 AU |
| Orbital Period | 2.351 days |
| Mean Orbital Velocity | 156.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.1900° |
| Mean Bulk Density | 1.29 g/cm³ (71.3 km/s vesc) |
| Insolation Flux | 947.8000 S⊕ (~1,289,956 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | — |