LP 890-9 c
Astrophysical Synthesis & Habitability Characterization
LP 890-9 c is a confirmed super-earth exoplanet orbiting the star LP 890-9, located approximately 105.8 light-years (32.43 parsecs) from the Solar System. First announced in 2022 by SPECULOOS Southern Observatory using the Transit detection technique (producing an estimated primary transit depth of 0.6487% across the stellar disk), this world measures 1.367 Earth radii and has a measured mass of 25.3 Earth masses. Combining its mass and radius yields a mean bulk density of 54.61 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 13.54 g⊕ (132.78 m/s²), and an escape velocity of 48.1 km/s.
In its orbital architecture around LP 890-9, LP 890-9 c completes one full revolution every 8.457 Earth days at a semi-major axis of 0.03984 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 51.2 km/s (compared to Earth's 29.8 km/s).
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 272 K (-1°C / +30°F) and an incident stellar irradiance of 0.91 S⊕ (~1,233 W/m²), LP 890-9 c orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star LP 890-9 is classified as a low-mass red dwarf of spectral type M6 V with an effective photospheric temperature of 2,850 K, a radius of 0.1556 R☉, a mass of 0.118 M☉, an estimated bolometric luminosity of 0.00143 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.2 Gyr and a metallicity of [Fe/H] = -0.028 dex (near-solar heavy-element abundance). From Earth, LP 890-9 shines at apparent V-band magnitude 18 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The LP 890-9 system is a multi-planet architecture hosting 2 confirmed worlds, with LP 890-9 c sharing its stellar neighborhood alongside LP 890-9 b.
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: SPECULOOS Southern Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | LP 890-9 |
| Spectral Type | M6 V |
| Effective Temp (Teff) | 2,850 K |
| Stellar Radius | 0.1556 R☉ |
| Stellar Mass | 0.1180 M☉ |
| Bolometric Luminosity | 0.00143 L☉ |
| Metallicity [Fe/H] | -0.028 dex |
| Stellar Age | 7.200 Gyr |
| Apparent Magnitude | V: 18.000 · G: 15.821 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.039840 AU |
| Orbital Period | 8.457 days |
| Mean Orbital Velocity | 51.2 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.2870° |
| Mean Bulk Density | 54.61 g/cm³ (48.1 km/s vesc) |
| Insolation Flux | 0.9060 S⊕ (~1,233 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 105.800 LY (32.430 pc) |