LP 791-18
High proper motion red dwarf in Crater
From Wikipedia, the free encyclopedia
LP 791-18 (TOI-736) is a cool M dwarf star in the constellation Crater, located 26.65 parsecs (86.9 light-years) away from Earth.[3] The star is one of the smallest known stars to host exoplanets.[5] In 2019 two exoplanets in transit around it were announced by TESS,[3] and a third planet was discovered in Spitzer Space Telescope data in 2023.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Crater[1] |
| Right ascension | 11h 02m 45.95462s[2] |
| Declination | −16° 24′ 22.2882″[2] |
| Apparent magnitude (V) | 16.9±0.2[3] |
| Characteristics | |
| Evolutionary stage | Red dwarf (main sequence) |
| Spectral type | M6.1±0.7V[3] |
| Astrometry | |
| Proper motion (μ) | RA: -221.291 mas/yr[2] Dec.: -58.841 mas/yr[2] |
| Parallax (π) | 37.5225±0.0392 mas[2] |
| Distance | 86.92 ± 0.09 ly (26.65 ± 0.03 pc) |
| Details[3] | |
| Mass | 0.139±0.005 M☉ |
| Radius | 0.17±0.018 R☉ |
| Temperature | 2960±55 K |
| Metallicity [Fe/H] | -0.09±0.19 dex |
| Age | 0.5±0.064 Gyr |
| Other designations | |
| LP 791-18, TOI-736, TIC 181804752, 2MASS J11024596-1624222[4] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Planetary system
The innermost planet, b, is a super-Earth and the outermost planet, c, is a mini-Neptune. They were discovered together in 2019.[3] The middle planet, d, is an Earth-mass world discovered in 2023. It may potentially be tidally heated by interactions with planet c, which would lead to abundant volcanoes similar to Jupiter's moon Io.[5] As the planet d is in the inner edge of the habitable zone, liquid water could condense on the side of the planet that faces away from the host star.[6]
In 2021 planet c was suggested for atmospheric analysis by the James Webb Space Telescope (JWST).[7] In 2025, by using JWST the atmosphere of planet c was found to be rich in haze and methane (CH4) but without clear evidence for carbon dioxide (CO2), which is unlike that of other temperate sub-Neptune planets including K2-18b and TOI-270d.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | — | 0.00978±0.00012 | 0.9479981±0.0000021 | — | 88.37+0.94 −0.95° |
1.212+0.059 −0.058 R🜨 |
| d | 0.91±0.19 M🜨 | 0.01992±0.00014 | 2.753436±0.000013 | 0.0011+0.0010 −0.0008 |
89.34±0.41° | 1.032+0.044 −0.043 R🜨 |
| c | 7.16±0.65 M🜨 | 0.02961+0.00035 −0.00036 |
4.9899100+0.0000012 −0.0000014 |
0.0001±0.0001 | 89.94±0.05° | 2.488±0.096 R🜨 |