Astronomy:LHS 1478 b
| Discovery[1] | |
|---|---|
| Discovered by | M. G. Soto, et al. |
| Discovery site | TESS |
| Discovery date | February 2021 |
| Transit | |
| Designations | |
| TOI-1640 b | |
| Orbital characteristics[2] | |
| 0.01872±0.00015 astronomical unit|AU | |
| Eccentricity | 0.038+0.16 −0.033 |
| Orbital period | 1.94953941(50) d |
| Inclination | 87.69°+0.41° −0.22° |
| 86.2°+4.5° −130° | |
| Semi-amplitude | 3.12±0.62 m/s |
| Star | LHS 1478 |
| Physical characteristics[2] | |
| Mean radius | 1.174±0.055 R🜨 |
| Mass | 2.27±0.45 M🜨 |
| Mean density | 7.7+2.0 −1.7 g/cm3 |
| Physics | 597.3+11 −7.0 K (324.1 °C; 615.5 °F, equilibrium) |
LHS 1478 b is a super-Earth exoplanet orbiting around LHS 1478, a red dwarf star located 59.4 light-years from Earth in the constellation of Cassiopeia.[3] It orbits at a distance of 0.018 AU from the star with a inclination of 87° to the plane of the sky. It takes LHS 1478b roughly 1.9 days to complete an orbit around the star.[4]
It has a mass of 2.27 Earths and a radius of 1.17 Earths. It has a bulk density of 7.7 g cm−3 making it consistent with a terrestrial planet with a composition mainly of Fe (~30%) and MgSiO3(~70%). It is classed as a hot super-Earth with an equilibrium temperature of 585 Kelvin receiving 21 times more energy from its star than Earth does from the Sun. This makes it impossible for water to remain a liquid on the surface suggesting that LHS 1478b may have a Venus-like atmosphere.[2][1]
The star it orbits around is a fairly inactive red dwarf star allowing for favorable conditions for spectroscopic studies with the James Webb Space Telescope (JWST). This places LHS 1478b with a family of small rocky planets (GJ 357 b, GJ 1132 b and GJ 486 b) where meaningful and realistic measurements with JWST can be taken.[1] JWST observations disfavor the possibility of a low-albedo bare rock, suggesting that the planet either has an atmosphere or a high albedo without an atmosphere.[2]
References
- ↑ 1.0 1.1 1.2 Soto, M. G.; Anglada-Escudé, G.; Dreizler, S.; Molaverdikhani, K.; Kemmer, J.; Rodríguez-López, C.; Lillo-Box, J.; Pallé, E. et al. (2021-05-01). "Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)" (in en). Astronomy & Astrophysics 649: A144. doi:10.1051/0004-6361/202140618. ISSN 0004-6361. Bibcode: 2021A&A...649A.144S. https://www.aanda.org/articles/aa/abs/2021/05/aa40618-21/aa40618-21.html.
- ↑ 2.0 2.1 2.2 2.3 August, P. C.; Buchhave, L. A.; Diamond-Lowe, H.; Mendonça, J. M.; Gressier, A.; Rathcke, A. D.; Allen, N. H.; Fortune, M. et al. (2025-03-01). "Hot Rocks Survey I: A possible shallow eclipse for LHS 1478 b" (in en). Astronomy & Astrophysics 695: A171. doi:10.1051/0004-6361/202452611. ISSN 0004-6361. Bibcode: 2025A&A...695A.171A. https://www.aanda.org/articles/aa/abs/2025/03/aa52611-24/aa52611-24.html.
- ↑ "★ LHS 1478" (in en). https://www.stellarcatalog.com/stars/lhs-1478.
- ↑ "LHS 1478 | NASA Exoplanet Archive". https://exoplanetarchive.ipac.caltech.edu/overview/LHS%201478.
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