HD 191939#Planetary system
{{Short description|Star in the constellation Draco}}
{{Starbox begin
| name = HD 191939
}}
{{Starbox image
| image = 250px
| caption = Location of HD 191939 in the night sky. The star is marked within the red diamond.
}}
{{Starbox observe
| constell = Draco
| dec = {{DEC|+66|51|02.0766}}
}}
{{Starbox character
|component1 = HD 191939
| type = main sequence
| u-b =
| b-v =
| v-r =
| r-i =
}}
{{Starbox astrometry
| radial_v = {{val|-9.23|0.16}}
| prop_mo_ra = {{val|150.194|0.015}}
| prop_mo_dec = {{val|-63.988|0.017}}
| parallax = 18.6967
| p_error = 0.0133
| absmag_v = 5.32
}}
{{Starbox detail
| component1 = HD 191939
| mass = {{val|0.81|0.04}}
| radius = {{val|0.94|0.02}}
| gravity = {{val|4.3|0.1}}
| luminosity_bolometric = {{val|0.65|0.02}}
| luminosity_visual =
| temperature = {{val|5348|100}}
| metal_fe = {{val|-0.15|0.06}}
| rotation =
| rotational_velocity = {{val|0.6|0.5}}
}}
{{Starbox catalog
| names = {{odlist | HD = 191939 | HIP = 99175 | TYC = 4244-964-1 | 2MASS = J20080574+6651019 | Gaia DR2 = 2248126315275354496 | TOI = 1339 | TIC = 269701147}}
}}
{{Starbox reference
| Simbad = HD+191939
| NSTED = HD 191939
| ARICNS =
| EPE = HD+191939
}}
{{starbox end
}}
HD 191939 is a single yellow (G-type) main-sequence star, located approximately 174 light-years away in the constellation of Draco, taking its primary name from its Henry Draper Catalogue designation.
Characteristics
HD 191939 is a Sun-like G-type main-sequence star, likely older than the Sun and relatively depleted in metals.
Planetary system
In 2020, an analysis carried out by a team of astronomers led by astronomer Mariona Badenas-Agusti of the TESS project confirmed the existence of three gaseous planets, all smaller than Neptune, in orbit around HD 191939. Another non-transiting gas giant planet designated HD 191939 e was detected in 2021, along with a substellar object on a highly uncertain, 9 to 46 year orbit. In 2022, a sixth planet, with a mass comparable to Uranus, was discovered in the system's habitable zone. The 2021 study also suggested the possible presence of an additional non-transiting planet with a period of 17.7 days, but the 2022 study did not support this.
{{OrbitboxPlanet begin
}}
{{OrbitboxPlanet
| exoplanet = b
| mass_earth = {{val|10.00|0.70}}
| radius_earth = {{val|3.410|0.075}}
| period = 8.8803256
| semimajor = {{val|0.0804|0.0025|0.0023}}
| eccentricity = {{val|0.031|0.010|0.011}}
| inclination = {{val|88.10|0.14|0.10}}
}}
{{OrbitboxPlanet
| exoplanet = c
| mass_earth = {{val|8.0|1.0}}
| radius_earth = {{val|3.195|0.075}}
| period = 28.579743
| semimajor = {{val|0.1752|0.0055|0.0050}}
| eccentricity = {{val|0.034|0.034|0.013}}
| inclination = {{val|89.10|0.06|0.08}}
}}
{{OrbitboxPlanet
| exoplanet = d
| mass_earth = {{val|2.80|0.60}}
| radius_earth = {{val|2.995|0.070}}
| period = 38.353037
| semimajor = {{val|0.2132|0.0065|0.0061}}
| eccentricity = {{val|0.031|0.018|0.012}}
| inclination = {{val|89.49|0.05|0.08}}
}}
{{OrbitboxPlanet
| exoplanet = e
| mass_earth = {{val|112.2|4.0|p=≥}}
| radius_earth =
| period = {{val|101.12|0.13}}
| semimajor = {{val|0.407|0.012}}
| eccentricity = {{val|0.031|0.008|0.016}}
| inclination = {{val|88.7|0.7}}
}}
{{OrbitboxPlanet
| exoplanet = g
| mass_earth = {{val|13.5|2.0|p=≥}}
| period = {{val|284|10|8}}
| semimajor = {{val|0.812|0.028}}
| eccentricity = {{val|0.030|0.025|0.011}}
}}
{{OrbitboxPlanet
| exoplanet = f
| mass = >2.08
| period = >2200
| semimajor = >3.2
}}
{{Orbitbox end}}
See also
- List of extrasolar planets
- List of exoplanets discovered in 2020 (HD 191939 b, c and d)
- List of exoplanets discovered in 2021 (HD 191939 e)
- List of exoplanets discovered in 2022 (HD 191939 f & g)
References
{{Reflist|refs=
{{cite simbad |title=HD 191939}}
{{Cite Gaia DR3|2248126315275354496}}
}}
{{Sky|20|08|5.75|+|+66|51|2.1}}
{{2020 in space}}{{2021 in space}}{{Stars of Draco}}
{{DEFAULTSORT:HD 191939}}
Category:G-type main-sequence stars
Category:Draco (constellation)