GJ 3988 b

Astrophysical Synthesis & Habitability Characterization

GJ 3988 b is a confirmed super-earth exoplanet orbiting the star GJ 3988, located approximately 32.3 light-years (9.91 parsecs) from the Solar System. First announced in 2023 by Calar Alto Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.74 Earth radii and has a measured mass of 3.69 Earth masses. Combining its mass and radius yields a mean bulk density of 3.86 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 16.3 km/s.

In its orbital architecture around GJ 3988, GJ 3988 b completes one full revolution every 6.944 Earth days at a semi-major axis of 0.0405 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 63.4 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.

ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for GJ 3988 b place it outside the conservative habitable zone definition pending further atmospheric characterization.

The host star GJ 3988 is classified as a low-mass red dwarf of spectral type M4.5 V with an effective photospheric temperature of 3,273 K, a radius of 0.1973 R☉, a mass of 0.1842 M☉, an estimated bolometric luminosity of 0.00401 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.12 dex (metal-poor relative to the Sun). From Earth, GJ 3988 shines at apparent V-band magnitude 13.627 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

Discovery Facility: Calar Alto Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).