ome Ser b
Astrophysical Synthesis & Habitability Characterization
ome Ser b is a confirmed gas giant exoplanet orbiting the star ome Ser, located approximately 250.3 light-years (76.76 parsecs) from the Solar System. First announced in 2013 by Okayama Astrophysical Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14 Earth radii (1.25 Jupiter radii) and has a measured mass of 233.922 Earth masses (0.74 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.47 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 45.7 km/s.
In its orbital architecture around ome Ser, ome Ser b completes one full revolution every 278.59 Earth days at a semi-major axis of 0.838 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 32.7 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.18 carries the world between 0.6872 AU at periapsis and 0.9888 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 825 K (+552°C / +1026°F) and receiving 77.15 S⊕ (~105,005 W/m²), ome Ser b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star ome Ser is classified as a solar-type yellow star of spectral type G8 III with an effective photospheric temperature of 4,724 K, a radius of 10.99 R☉, a mass of 1.01 M☉, an estimated bolometric luminosity of 53.967 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.12 dex (metal-poor relative to the Sun). From Earth, ome Ser shines at apparent V-band magnitude 5.216 (visible to the unaided human eye under dark skies) 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: Okayama Astrophysical Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | ome Ser |
| Spectral Type | G8 III |
| Effective Temp (Teff) | 4,724 K |
| Stellar Radius | 10.9900 R☉ |
| Stellar Mass | 1.0100 M☉ |
| Bolometric Luminosity | 53.967 L☉ |
| Metallicity [Fe/H] | -0.120 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 5.216 · G: 4.928 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.838000 AU |
| Orbital Period | 278.59 days |
| Mean Orbital Velocity | 32.7 km/s |
| Orbital Eccentricity (e) | 0.18000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.47 g/cm³ (45.7 km/s vesc) |
| Insolation Flux | 77.1527 S⊕ (~105,005 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 250.300 LY (76.756 pc) |