KOINTREAU-1 b
Astrophysical Synthesis & Habitability Characterization
KOINTREAU-1 b is a confirmed gas giant exoplanet orbiting the star XEST 17-036, located approximately 517.3 light-years (158.62 parsecs) from the Solar System. First announced in 2026 by W. M. Keck Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 12.4 Earth radii (1.11 Jupiter radii) and has a measured mass of 3368.981 Earth masses (10.6 Jupiter masses). Combining its mass and radius yields a mean bulk density of 9.74 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 21.91 g⊕ (214.86 m/s²), and an escape velocity of 184.4 km/s.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.400 R⊕, KOINTREAU-1 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star XEST 17-036 is classified as a low-mass red dwarf of spectral type M4 with an effective photospheric temperature of 3,551 K, a mass of 0.26 M☉. Stellar evolution modeling indicates an estimated stellar age of 0.003 Gyr and a metallicity of [Fe/H] = -0.15 dex (metal-poor relative to the Sun). From Earth, XEST 17-036 shines at apparent Gaia G-band magnitude 16.508 (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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | XEST 17-036 |
| Spectral Type | M4 |
| Effective Temp (Teff) | 3,551 K |
| Stellar Radius | — |
| Stellar Mass | 0.2600 M☉ |
| Metallicity [Fe/H] | -0.150 dex |
| Stellar Age | 0.003 Gyr |
| Apparent Magnitude | · G: 16.508 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 690.000000 AU |
| Orbital Period | — |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 9.74 g/cm³ (184.4 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 517.300 LY (158.618 pc) |