BD+48 740 b
Astrophysical Synthesis & Habitability Characterization
BD+48 740 b is a confirmed gas giant exoplanet orbiting the star BD+48 740, located approximately 2174.1 light-years (666.59 parsecs) from the Solar System. First announced in 2018 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.5 Earth radii (1.2 Jupiter radii) and has a measured mass of 540.311 Earth masses (1.7 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.21 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.96 g⊕ (29.03 m/s²), and an escape velocity of 70.8 km/s.
In its orbital architecture around BD+48 740, BD+48 740 b completes one full revolution every 733 Earth days (2.01Julian years) at a semi-major axis of 1.7 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 25.2 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.76, swinging from 0.408 AU at periapsis out to 2.992 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 539 K (+266°C / +511°F) and receiving 15.10 S⊕ (~20,557 W/m²), BD+48 740 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star BD+48 740 is classified as an orange K-type star of spectral type K3 III with an effective photospheric temperature of 4,534 K, a radius of 10.33 R☉, a mass of 1.09 M☉, an estimated bolometric luminosity of 40.459 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.13 dex (metal-poor relative to the Sun). From Earth, BD+48 740 shines at apparent V-band magnitude 8.69 (accessible to binoculars and small amateur telescopes) 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | BD+48 740 |
| Spectral Type | K3 III |
| Effective Temp (Teff) | 4,534 K |
| Stellar Radius | 10.3300 R☉ |
| Stellar Mass | 1.0900 M☉ |
| Bolometric Luminosity | 40.459 L☉ |
| Metallicity [Fe/H] | -0.130 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 8.690 · G: 8.264 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.700000 AU |
| Orbital Period | 733 days |
| Mean Orbital Velocity | 25.2 km/s |
| Orbital Eccentricity (e) | 0.76000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.21 g/cm³ (70.8 km/s vesc) |
| Insolation Flux | 15.1044 S⊕ (~20,557 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2174.100 LY (666.589 pc) |