TOI-2587 A b
Astrophysical Synthesis & Habitability Characterization
TOI-2587 A b is a confirmed gas giant exoplanet orbiting the star TOI-2587 A, located approximately 1218.8 light-years (373.68 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 0.4112% across the stellar disk), this world measures 12.072 Earth radii (1.08 Jupiter radii) and has a measured mass of 69.287 Earth masses (0.22 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.22 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.48 g⊕ (4.71 m/s²), and an escape velocity of 26.8 km/s.
In its orbital architecture around TOI-2587 A, TOI-2587 A b completes one full revolution every 5.457 Earth days at a semi-major axis of 0.0635 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 126.6 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 1445 K (+1172°C / +2142°F) and receiving 728.00 S⊕ (~990,808 W/m²), TOI-2587 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2587 A is classified as a stellar host with an effective photospheric temperature of 5,760 K, a radius of 1.726 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 2.942 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.7 Gyr and a metallicity of [Fe/H] = 0.13 dex (metal-rich relative to the Sun). From Earth, TOI-2587 A shines at apparent V-band magnitude 11.544 (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-2587 A |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,760 K |
| Stellar Radius | 1.7260 R☉ |
| Stellar Mass | 1.1500 M☉ |
| Bolometric Luminosity | 2.942 L☉ |
| Metallicity [Fe/H] | 0.130 dex |
| Stellar Age | 6.700 Gyr |
| Apparent Magnitude | V: 11.544 · G: 11.408 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.063500 AU |
| Orbital Period | 5.457 days |
| Mean Orbital Velocity | 126.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 84.8100° |
| Mean Bulk Density | 0.22 g/cm³ (26.8 km/s vesc) |
| Insolation Flux | 728.0000 S⊕ (~990,808 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1218.800 LY (373.675 pc) |