NASA (Exoplanet Catalog artwork)LP 791-18 d
An Earth-sized world probably as volcanic as Jupiter's moon Io
Overview
LP 791-18 d is a super Earth exoplanet that orbits a M-type star. Its mass is 0.91 Earths, it takes 2.8 days to complete one orbit of its star, and is 0.01992 AU from its star. Its discovery was announced in 2023.
Source: NASA Exoplanet Catalog
Why it matters
- Found in 2023; a neighbouring sub-Neptune tugs its orbit into an ellipse, flexing and heating the interior.
- Sits at the inner edge of the habitable zone, 90 light-years away.
- Volcanism could sustain an atmosphere, making it a target for studying how airless worlds get air.
NASA puts it this way: “LP 791-18 d is a super Earth exoplanet that orbits an M-type star. Its mass is 0.9 Earths, it takes 2.8 days to complete one orbit of its star, and is 0.01992 AU from its star. Its discovery was announced in 2023.”
Discovery & system
- Discovered
- 2023 · Transit · Spitzer Space Telescope
- Discovery paper
- Peterson et al. 2023
- Host star
- LP 791-18 · M(6.1 +/- 0.7) V · 2,960 K · 0.14 M☉
- System
- 3 known planets
- Siblings
- LP 791-18 b, LP 791-18 c
The system
| World | Period | Distance | Radius | Mass | Temp. |
|---|---|---|---|---|---|
| LP 791-18 b | 22.8 h | 0.0098 AU | 1.21 R⊕ | 1.94 M⊕ | 564 K |
| LP 791-18 d | 2.75 d | 0.02 AU | 1.03 R⊕ | 0.91 M⊕ | 396 K |
| LP 791-18 c | 4.99 d | 0.03 AU | 2.49 R⊕ | 7.16 M⊕ | 324 K |
this worldhabitable zone 0.046 AU – 0.08 AUlog distance scaleorbital phases are arbitrarystar: M(6.1 +/- 0.7) V, 2,960 K
By the numbers
- Radius
- 1.03 R⊕6,575 km
- Mass
- 0.91 M⊕5.43 ×10²⁴ kg
- Orbital period
- 2.75 d0.01 yr
- Distance from star
- 0.02 AU2.98 million km
- Eccentricity
- 0.001nearly circular
- Equilibrium temp.
- 396 K122 °C
- Starlight received
- 6 × Earth
- Distance from Earth
- 86.4 ly26.5 pc
- Density
- 4.56 g/cm³0.83 × Earth
Sources
Image: NASA (Exoplanet Catalog artwork) · NASA media: generally free of copyright · image page
Text: NASA Exoplanet Catalog. Taglines and highlights are editorial.