L 168-9
{{Short description|Star in the constellation Tucana}}
{{Starbox begin
| name = L 168-9 / Danfeng
}}
{{Starbox observe
| epoch = J2000
| constell = Tucana{{cite web |url=http://djm.cc/constellation.html |title=Finding the constellation which contains given sky coordinates |date=2 August 2008 |website=djm.cc |access-date=30 August 2022 }}
| dec = {{DEC|-60|03|54.6447}}
| appmag_v = {{val|11.02|0.06}}
}}
{{Starbox character
| type = Main sequence
| appmag_1_passband = B
| appmag_1 = {{val|12.45|0.19}}
| appmag_2_passband = V
| appmag_2 = {{val|11.02|0.06}}
| appmag_3_passband = G
| appmag_3 = {{val|10.237|0.003}}
| appmag_4_passband = J
| appmag_4 = {{val|7.941|0.019}}
| appmag_5_passband = H
| appmag_5 = {{val|7.320|0.053}}
| appmag_6_passband = K
| appmag_6 = {{val|7.082|0.031}}
}}
{{Starbox astrometry
| radial_v = {{val|29.44|0.21}}
| prop_mo_ra = {{val|-319.924}}
| prop_mo_dec = {{val|-127.782}}
| parallax = 39.7113
| p_error = 0.0244
| absmag_v =
| absmag_bol =
}}
{{Starbox detail
| mass = {{val|0.614|0.055}}
| radius = {{val|0.604|0.037}}
| luminosity_bolometric = {{val|0.0723|0.0018}}
| habitable_inner =
| habitable_outer =
| gravity = {{val|4.84|0.08}}
| temperature = {{val|3842|32}}
| metal_fe = {{val|0.06|0.13}}
| rotation = {{val|29|2|ul=d}}
| rotational_velocity =
}}
{{Starbox catalog
| names = {{odlist | name = Danfeng | 2MASS = J23200751-6003545 | CD = -60 8051 | GJ = 4332 | HIP = 115211 | L = 168-9 | LTT = 9494 | NLTT = 56509 | PM = J23201-6003 | TIC = 234994474 | TOI = 134 | TYC = 9126-748-1 | WISEA = J232007.06-600355.8 }}
}}
{{Starbox reference
| Simbad = L+168-9
| NSTED = L-168-9
}}
{{Starbox end}}
L 168-9 (also known as GJ 4332 or TOI-134, officially named Danfeng) is a red dwarf star located {{convert|82.1|ly|pc|lk=on|abbr=off}} 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 {{convert|3842|K|C F|lk=on}} and a rotation period of 29 days. L 168-9 is orbited by one known exoplanet.
Nomenclature
The 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.{{cite web |url=https://www.nameexoworlds.iau.org/2022exoworlds |title=List of ExoWorlds 2022 |date=8 August 2022 |website=nameexoworlds.iau.org |publisher=IAU |access-date=27 August 2022}} The approved names, proposed by a team from China, were announced in June 2023. L 168-9 is named Danfeng (丹凤) and its planet is named Qingluan (青鸾), after mythological birds of ancient China.
Planetary system
The 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 {{convert|965|K|C F|lk=on}}. L 168-9 b is a target for observation and atmospheric characterization with the James Webb Space Telescope, and has been observed as one of its first targets.
A newer study refined the planetary parameters of L 168-9 b. The newer research found a lower mass of {{Earth mass|sym=y|4.07|link=y}} and a higher radius of {{earth radius|1.63|link=y}}. These parameters imply a lower density of {{val|5.18|u=g/cm3}}, in contrast to the previous value of {{val|9.6|u=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 {{val|998|39|u=K}}.
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.
{{Orbitbox planet begin
| name = L 168-9
}}
{{Orbitbox planet
| exoplanet = b / Qingluan
| mass_earth = {{val|4.07|0.45}}
| radius_earth = {{val|1.63|0.14}}
| semimajor = {{val|0.0208|0.0006}}
| period = {{val|1.40153|0}}
| inclination = {{val|84.27|1.01}}
}}
{{Orbitbox end}}
References
{{reflist|refs=
{{cite simbad |title=L 168-9 |access-date=30 August 2022}}
{{Cite Gaia DR3|6491962300492857472}}
{{cite journal |last1=Astudillo-Defru |first1=N. |last2=Cloutier |first2=R. |display-authors=etal |date=April 2020 |title=A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS |journal=Astronomy & Astrophysics |volume=636 |issue= |pages=A58 |doi=10.1051/0004-6361/201937179 |arxiv=2001.09175 |bibcode=2020A&A...636A..58A|s2cid=210920549 }}
{{cite journal |last1=Rigby |first1=Jane |last2=Perrin |first2=Marshall |last3=McElwain |first3=Michael |last4=Kimble |first4=Randy |last5=Friedman |first5=Scott |last6=Lallo |first6=Matt |last7=Doyon |first7=René |last8=Feinberg |first8=Lee |last9=Ferruit |first9=Pierre |last10=Glasse |first10=Alistair |last11=Rieke |first11=Marcia |display-authors=etal |date=April 2023 |title=The Science Performance of JWST as Characterized in Commissioning |journal=Publications of the Astronomical Society of the Pacific |volume=135 |issue=1046 |pages=048001 |doi=10.1088/1538-3873/acb293 |arxiv=2207.05632 |bibcode=2023PASP..135d8001R}}
{{cite journal |last1=Bouwman |first1=Jeroen |last2=Kendrew |first2=Sarah |display-authors=etal |date=March 2023 |title=Spectroscopic Time Series Performance of the Mid-infrared Instrument on the JWST |journal=Publications of the Astronomical Society of the Pacific |volume=135 |issue=1045 |pages=038002 |doi=10.1088/1538-3873/acbc49 |arxiv=2211.16123 |bibcode=2023PASP..135c8002B}}
{{cite web |url=https://www.nameexoworlds.iau.org/2022approved-names |title=2022 Approved Names |website=nameexoworlds.iau.org |publisher=IAU |access-date=7 June 2023}}
}}
{{Tucana}}
Category:M-type main-sequence stars