L 168-9 (also known as GJ 4332 or TOI-134, officially named Danfeng) is a red dwarf star located 82.1 light-years (25.2 parsecs) away from the Solar System in the constellation of Tucana. The star has about 61% the mass and 60% the radius of the Sun. It has a temperature of 3,842 K (3,569 °C; 6,456 °F) and a rotation period of 29 days. L 168-9 is orbited by one known exoplanet.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Tucana[1] |
| Right ascension | 23h 20m 07.52452s[2] |
| Declination | −60° 03′ 54.6447″[2] |
| Apparent magnitude (V) | 11.02±0.06[3] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | M1V[3] |
| Apparent magnitude (B) | 12.45±0.19[3] |
| Apparent magnitude (V) | 11.02±0.06[3] |
| Apparent magnitude (G) | 10.237±0.003[2] |
| Apparent magnitude (J) | 7.941±0.019[3] |
| Apparent magnitude (H) | 7.320±0.053[3] |
| Apparent magnitude (K) | 7.082±0.031[3] |
| Astrometry | |
| Radial velocity (Rv) | 29.44±0.21[2] km/s |
| Proper motion (μ) | RA: −319.924 mas/yr[2] Dec.: −127.782 mas/yr[2] |
| Parallax (π) | 39.7113 ± 0.0244 mas[2] |
| Distance | 82.13 ± 0.05 ly (25.18 ± 0.02 pc) |
| Details[4] | |
| Mass | 0.614±0.055 M☉ |
| Radius | 0.604±0.037 R☉ |
| Luminosity (bolometric) | 0.0723±0.0018 L☉ |
| Surface gravity (log g) | 4.84±0.08 cgs |
| Temperature | 3842±32 K |
| Metallicity [Fe/H] | 0.06±0.13 dex |
| Rotation | 29±2 d |
| Other designations | |
| Database references | |
| SIMBAD | data |
Nomenclature
editThe designation L 168-9 comes from Luyten's first catalogue of stars with high proper motion.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project.[6] The approved names, proposed by a team from China, were announced in June 2023. L 168-9 is named Danfeng and its planet is named Qingluan, after mythological birds of ancient China.[7]
Planetary system
editThe exoplanet L 168-9 b, officially named Qingluan, was discovered in 2020 using TESS. At the discovery, this terrestrial super-Earth was thought to have about 4.6 times the mass and 1.39 times the radius of Earth, and an estimated equilibrium temperature of 965 K (692 °C; 1,277 °F). L 168-9 b is a target for observation and atmospheric characterization with the James Webb Space Telescope,[3] and has been observed as one of its first targets.[8][9]
A newer study refined the planetary parameters of L 168-9 b. The newer research found a lower mass of 4.07 ME and a higher radius of 1.63 R🜨. These parameters imply a lower density of 5.18 g/cm3, in contrast to the previous value of 9.6 g/cm3. Given the lower density of the planet, it more likely has a pure rock composition, rather than a 50% iron core and 50% silicate mantle as previously proposed. The orbital parameters show little variation, while the equilibrium temperature was updated to 998±39 K.[4]
Transmission spectra of combined near- and mid-infrared observations by the James Webb Space Telescope showed no atmospheric features. However, further observations are required to rule out a thick (100 bar) carbon dioxide atmosphere, which could also explain the data.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Qingluan | 4.07±0.45 M🜨 | 0.0208±0.0006 | 1.40153±0 | <0.21[3] | 84.27±1.01° | 1.63±0.14 R🜨 |
References
edit- ^ "Finding the constellation which contains given sky coordinates". djm.cc. 2 August 2008. Retrieved 30 August 2022.
- ^ a b c d e f 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 g h i Astudillo-Defru, N.; Cloutier, R.; et al. (April 2020). "A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS". Astronomy & Astrophysics. 636: A58. arXiv:2001.09175. Bibcode:2020A&A...636A..58A. doi:10.1051/0004-6361/201937179. S2CID 210920549.
- ^ a b c Hobson, M. J.; Bouchy, F.; Lavie, B.; Lovis, C.; Adibekyan, V.; Prieto, C. Allende; Alibert, Y.; Barros, S. C. C.; Castro-González, A.; Cristiani, S.; D’Odorico, V.; Damasso, M.; Marcantonio, P. Di; Dumusque, X.; Ehrenreich, D. (2024-08-01). "Three super-Earths and a possible water world from TESS and ESPRESSO". Astronomy & Astrophysics. 688: A216. arXiv:2406.06278. doi:10.1051/0004-6361/202450505. ISSN 0004-6361.
- ^ "L 168-9". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 August 2022.
- ^ "List of ExoWorlds 2022". nameexoworlds.iau.org. IAU. 8 August 2022. Retrieved 27 August 2022.
- ^ "2022 Approved Names". nameexoworlds.iau.org. IAU. Retrieved 7 June 2023.
- ^ Rigby, Jane; Perrin, Marshall; McElwain, Michael; Kimble, Randy; Friedman, Scott; Lallo, Matt; Doyon, René; Feinberg, Lee; Ferruit, Pierre; Glasse, Alistair; Rieke, Marcia; et al. (April 2023). "The Science Performance of JWST as Characterized in Commissioning". Publications of the Astronomical Society of the Pacific. 135 (1046): 048001. arXiv:2207.05632. Bibcode:2023PASP..135d8001R. doi:10.1088/1538-3873/acb293.
- ^ Bouwman, Jeroen; Kendrew, Sarah; et al. (March 2023). "Spectroscopic Time Series Performance of the Mid-infrared Instrument on the JWST". Publications of the Astronomical Society of the Pacific. 135 (1045): 038002. arXiv:2211.16123. Bibcode:2023PASP..135c8002B. doi:10.1088/1538-3873/acbc49.
- ^ Alam, Munazza K.; et al. (5 November 2024). "JWST COMPASS: The first near- to mid-infrared transmission spectrum of the hot super-Earth L 168-9 b". arXiv:2411.03154.