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]
| 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 | |
| Database references | |
| SIMBAD | data |
The star is one of the smallest known 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]
Planetary system
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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.[7]
| 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 | 0.9+0.5 −0.4 M🜨 |
0.01992±0.00014 | 2.753436±0.000013 | 0.0015±0.00014 | 89.34±0.41° | 1.032+0.044 −0.043 R🜨 |
| c | 7.1±0.7 M🜨 | 0.02961+0.00035 −0.00036 |
4.9899093+0.0000074 −0.0000072 |
0.00008±0.00004 | 89.78±0.13° | 2.438±0.096 R🜨 |
References
edit- ^ "Finding the constellation which contains given sky coordinates". djm.cc. 2 August 2008.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f Crossfield, Ian J. M.; Waalkes, William; Newton, Elisabeth R.; Narita, Norio; Muirhead, Philip; Ment, Kristo; et al. (2019). "A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18". The Astrophysical Journal Letters. 883 (1): L16. arXiv:1906.09267. Bibcode:2019ApJ...883L..16C. doi:10.3847/2041-8213/ab3d30.
- ^ "LP 791-18". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 19 May 2023.
- ^ a b c d Peterson, Merrin S; Benneke, Björn; Collins, Karen; Piaulet, Caroline; Crossfield, Ian JM; Ali-Dib, Mohamad; et al. (2023). "A temperate Earth-sized planet with tidal heating transiting an M6 star". Nature. 617 (7962): 701–705. doi:10.1038/s41586-023-05934-8. hdl:11603/28165. PMID 37198481.
- ^ a b Kazmierczak, Jeanette (16 May 2023). "NASA's Spitzer, TESS Find Potentially Volcano-Covered Earth-Size World". NASA. Retrieved 19 May 2023.
- ^ Phillips, Caprice L.; Wang, Ji; Kendrew, Sarah; Greene, Thomas P.; Hu, Renyu; Valenti, Jeff; Panero, Wendy R.; Schulze, Joseph (2021). "Detecting Biosignatures in the Atmospheres of Gas Dwarf Planets with the James Webb Space Telescope". The Astrophysical Journal. 923 (2): 144. arXiv:2109.12132. Bibcode:2021ApJ...923..144P. doi:10.3847/1538-4357/ac29be.