MXB 1658-298 b
Astrophysical Synthesis & Habitability Characterization
MXB 1658-298 b is a confirmed gas giant exoplanet orbiting the star MXB 1658-298. First announced in 2017 by Multiple Observatories using the Eclipse Timing Variations detection technique, this world measures 12 Earth radii (1.07 Jupiter radii) and has a measured mass of 7532.571 Earth masses (23.7 Jupiter masses). Combining its mass and radius yields a mean bulk density of 24.04 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 52.31 g⊕ (512.99 m/s²), and an escape velocity of 280.3 km/s.
In its orbital architecture around MXB 1658-298, MXB 1658-298 b completes one full revolution every 760 Earth days (2.08Julian years) at a semi-major axis of 1.613 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 23.1 km/s (compared to Earth's 29.8 km/s).
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.000 R⊕, MXB 1658-298 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 MXB 1658-298 is classified as a stellar host with a mass of 1.98 M☉.
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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | MXB 1658-298 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | — |
| Stellar Radius | — |
| Stellar Mass | 1.9800 M☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | — |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.613000 AU |
| Orbital Period | 760 days |
| Mean Orbital Velocity | 23.1 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 24.04 g/cm³ (280.3 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | — |