K2-49 b

Astrophysical Synthesis & Habitability Characterization

K2-49 b is a confirmed super-earth exoplanet orbiting the star K2-49, located approximately 1490.9 light-years (457.13 parsecs) from the Solar System. First announced in 2016 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.1546% across the stellar disk), this world measures 1.93 Earth radii and has a measured mass of 4.38 Earth masses. Combining its mass and radius yields a mean bulk density of 3.36 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.18 g⊕ (11.57 m/s²), and an escape velocity of 16.9 km/s.

In its orbital architecture around K2-49, K2-49 b completes one full revolution every 2.771 Earth days at a semi-major axis of 0.0309 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 121.3 km/s (compared to Earth's 29.8 km/s).

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 768 K (+495°C / +923°F) and receiving 59.00 S⊕ (~80,299 W/m²), K2-49 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star K2-49 is classified as a stellar host with an effective photospheric temperature of 4,175 K, a radius of 0.45 R☉, a mass of 0.51 M☉, an estimated bolometric luminosity of 0.055 L☉. From Earth, K2-49 shines at apparent V-band magnitude 15.668 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

Discovery Facility: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).