psi1 Dra B b
Astrophysical Synthesis & Habitability Characterization
psi1 Dra B b is a confirmed gas giant exoplanet orbiting the star psi1 Dra B, located approximately 74.1 light-years (22.72 parsecs) from the Solar System. First announced in 2015 by McDonald Observatory 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 486.28 Earth masses (1.53 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.09 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.67 g⊕ (26.18 m/s²), and an escape velocity of 67.1 km/s.
In its orbital architecture around psi1 Dra B, psi1 Dra B b completes one full revolution every 3117 Earth days (8.53Julian years) at a semi-major axis of 4.43 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 15.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.4, swinging from 2.658 AU at periapsis out to 6.202 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 159 K (-114°C / -173°F) and an incident flux of 0.11 S⊕ (~147 W/m²), surface water and volatile species on psi1 Dra B b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star psi1 Dra B is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 6,212 K, a radius of 1.2557 R☉, a mass of 1.19 M☉, an estimated bolometric luminosity of 2.107 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.3 Gyr and a metallicity of [Fe/H] = 0.01 dex (near-solar heavy-element abundance). From Earth, psi1 Dra B shines at apparent V-band magnitude 5.808 (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: McDonald Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | psi1 Dra B |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 6,212 K |
| Stellar Radius | 1.2557 R☉ |
| Stellar Mass | 1.1900 M☉ |
| Bolometric Luminosity | 2.107 L☉ |
| Metallicity [Fe/H] | 0.010 dex |
| Stellar Age | 3.300 Gyr |
| Apparent Magnitude | V: 5.808 · G: 5.648 |
| System Architecture | 3 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 4.430000 AU |
| Orbital Period | 3117 days |
| Mean Orbital Velocity | 15.5 km/s |
| Orbital Eccentricity (e) | 0.40000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.09 g/cm³ (67.1 km/s vesc) |
| Insolation Flux | 0.1079 S⊕ (~147 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 74.100 LY (22.719 pc) |