HD 15337 b
Astrophysical Synthesis & Habitability Characterization
HD 15337 b is a confirmed super-earth exoplanet orbiting the star HD 15337, located approximately 146.2 light-years (44.82 parsecs) from the Solar System. First announced in 2019 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.036% across the stellar disk), this world measures 1.77 Earth radii and has a measured mass of 6.519 Earth masses. Combining its mass and radius yields a mean bulk density of 6.48 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 2.08 g⊕ (20.4 m/s²), and an escape velocity of 21.5 km/s.
In its orbital architecture around HD 15337, HD 15337 b completes one full revolution every 4.756 Earth days at a semi-major axis of 0.05245 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 120 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.058 carries the world between 0.0494 AU at periapsis and 0.0555 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1001 K (+728°C / +1342°F) and receiving 404.56 S⊕ (~550,605 W/m²), HD 15337 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 15337 is classified as an orange K-type star of spectral type K1 V with an effective photospheric temperature of 5,131 K, a radius of 0.855 R☉, a mass of 0.829 M☉, an estimated bolometric luminosity of 0.455 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.6 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, HD 15337 shines at apparent V-band magnitude 9.1 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 15337 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 15337 b sharing its stellar neighborhood alongside HD 15337 c.
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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 15337 |
| Spectral Type | K1 V |
| Effective Temp (Teff) | 5,131 K |
| Stellar Radius | 0.8550 R☉ |
| Stellar Mass | 0.8290 M☉ |
| Bolometric Luminosity | 0.455 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 9.600 Gyr |
| Apparent Magnitude | V: 9.100 · G: 8.856 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.052450 AU |
| Orbital Period | 4.756 days |
| Mean Orbital Velocity | 120 km/s |
| Orbital Eccentricity (e) | 0.05800 |
| Orbital Inclination (i) | 89.3000° |
| Mean Bulk Density | 6.48 g/cm³ (21.5 km/s vesc) |
| Insolation Flux | 404.5595 S⊕ (~550,605 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 146.200 LY (44.816 pc) |