BEBOP-4 AB b

Astrophysical Synthesis & Habitability Characterization

BEBOP-4 AB b is a confirmed gas giant exoplanet orbiting the star BEBOP-4 A, located approximately 764.2 light-years (234.29 parsecs) from the Solar System. First announced in 2025 by Haute-Provence Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world has a minimum or true mass of 8358.887 Earth masses (26.3 M♃), while its physical transit radius has not yet been geometrically observed.

In its orbital architecture around BEBOP-4 A, BEBOP-4 AB b completes one full revolution every 1823.5 Earth days (4.99Julian years) at a semi-major axis of 3.634 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 21.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.428, swinging from 2.0786 AU at periapsis out to 5.1894 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.

✓ Classified as a Temperate Habitable Zone Candidate.

With an estimated equilibrium temperature of 239 K (-34°C / -29°F) and an incident stellar irradiance of 0.55 S⊕ (~745 W/m²), BEBOP-4 AB b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.

The host star BEBOP-4 A is classified as a solar-type yellow star of spectral type G3 V with an effective photospheric temperature of 5,701 K, a radius of 2.7565 R☉, a mass of 1.507 M☉, an estimated bolometric luminosity of 7.201 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.262 dex (metal-rich relative to the Sun). From Earth, BEBOP-4 A shines at apparent V-band magnitude 9.646 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere.

Discovery Facility: Haute-Provence Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).