OGLE2-TR-L9 b
Astrophysical Synthesis & Habitability Characterization
OGLE2-TR-L9 b is a confirmed gas giant exoplanet orbiting the star OGLE2-TR-L9, located approximately 5308.6 light-years (1627.63 parsecs) from the Solar System. First announced in 2008 by OGLE using the Transit detection technique (producing an estimated primary transit depth of 1.1693% across the stellar disk), this world measures 18.046 Earth radii (1.61 Jupiter radii) and has a measured mass of 1430.175 Earth masses (4.5 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.34 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 4.39 g⊕ (43.05 m/s²), and an escape velocity of 99.6 km/s.
In its orbital architecture around OGLE2-TR-L9, OGLE2-TR-L9 b completes one full revolution every 2.486 Earth days at a semi-major axis of 0.0308 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 134.8 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 2034 K (+1761°C / +3202°F) and receiving 4,135.45 S⊕ (~5,628,345 W/m²), OGLE2-TR-L9 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star OGLE2-TR-L9 is classified as a stellar host with an effective photospheric temperature of 6,933 K, a radius of 1.53 R☉, a mass of 1.52 M☉, an estimated bolometric luminosity of 4.852 L☉. Stellar evolution modeling indicates an estimated stellar age of 1 Gyr and a metallicity of [Fe/H] = -0.05 dex (near-solar heavy-element abundance). From Earth, OGLE2-TR-L9 shines at apparent V-band magnitude 14.718 (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: OGLE · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | OGLE2-TR-L9 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,933 K |
| Stellar Radius | 1.5300 R☉ |
| Stellar Mass | 1.5200 M☉ |
| Bolometric Luminosity | 4.852 L☉ |
| Metallicity [Fe/H] | -0.050 dex |
| Stellar Age | 1.000 Gyr |
| Apparent Magnitude | V: 14.718 · G: 14.564 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.030800 AU |
| Orbital Period | 2.486 days |
| Mean Orbital Velocity | 134.8 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 79.8000° |
| Mean Bulk Density | 1.34 g/cm³ (99.6 km/s vesc) |
| Insolation Flux | 4135.4482 S⊕ (~5,628,345 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 5308.600 LY (1627.630 pc) |