DMPP-1 d
Astrophysical Synthesis & Habitability Characterization
DMPP-1 d is a confirmed sub-neptune exoplanet orbiting the star DMPP-1, located approximately 204 light-years (62.54 parsecs) from the Solar System. First announced in 2019 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 2.02 Earth radii and has a measured mass of 4.72 Earth masses. Combining its mass and radius yields a mean bulk density of 3.16 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.16 g⊕ (11.38 m/s²), and an escape velocity of 17.1 km/s.
In its orbital architecture around DMPP-1, DMPP-1 d completes one full revolution every 3.142 Earth days at a semi-major axis of 0.04467 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 154.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.36, swinging from 0.0286 AU at periapsis out to 0.0608 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1632 K (+1359°C / +2478°F) and receiving 1,045.96 S⊕ (~1,423,551 W/m²), DMPP-1 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star DMPP-1 is classified as a warm F-type star of spectral type F8 V with an effective photospheric temperature of 6,196 K, a radius of 1.26 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 2.099 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.01 Gyr. From Earth, DMPP-1 shines at apparent V-band magnitude 7.98 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The DMPP-1 system is a multi-planet architecture hosting 4 confirmed worlds, with DMPP-1 d sharing its stellar neighborhood alongside DMPP-1 e, DMPP-1 c, DMPP-1 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | DMPP-1 |
| Spectral Type | F8 V |
| Effective Temp (Teff) | 6,196 K |
| Stellar Radius | 1.2600 R☉ |
| Stellar Mass | 1.2100 M☉ |
| Bolometric Luminosity | 2.099 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 2.010 Gyr |
| Apparent Magnitude | V: 7.980 · G: 7.850 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.044670 AU |
| Orbital Period | 3.142 days |
| Mean Orbital Velocity | 154.7 km/s |
| Orbital Eccentricity (e) | 0.36000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 3.16 g/cm³ (17.1 km/s vesc) |
| Insolation Flux | 1045.9594 S⊕ (~1,423,551 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 204.000 LY (62.539 pc) |