HD 30856
  | |
| Observation data Epoch J2000.0[1] Equinox J2000.0[1] | |
|---|---|
| Constellation | Eridanus[2] |
| Right ascension | 04h 50m 17.8614408264s[1] |
| Declination | −24° 22′ 07.833769068″[1] |
| Apparent magnitude (V) | 7.911[1][3] |
| Characteristics | |
| Evolutionary stage | Red-giant branch star[1] |
| Spectral type | K0III[1][3] |
| B−V color index | 0.961[1][3] |
| Astrometry | |
| Radial velocity (Rv) | 35.71[1] km/s |
| Proper motion (μ) | RA: 18.469[1] mas/yr Dec.: −19.837[1] mas/yr |
| Parallax (π) | 7.5965 ± 0.0179 mas[1] |
| Distance | 429 ± 1 ly (131.6 ± 0.3 pc) |
| Orbit[4] | |
| Primary | HD 30856 A |
| Companion | HD 30856 B |
| Semi-major axis (a) | 0.786″ |
| Details | |
| HD 30856 A | |
| Mass | 1.17[5] / 1.35[4] M☉ |
| Radius | 4.40[5] R☉ |
| Luminosity | 9.9±0.5[6] L☉ |
| Surface gravity (log g) | 3.20[5] cgs |
| Temperature | 4895[5] / 4982 ± 44[4] K |
| Metallicity [Fe/H] | −0.06±0.03[6] dex |
| Rotational velocity (v sin i) | 2.85[6] km/s |
| HD 30856 B | |
| Mass | 0.54±0.01[4] M☉ |
| Surface gravity (log g) | 4.7[4] cgs |
| Temperature | 3700–4150[4] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 30856 (proper name Mouhoun) is a binary system between HD 30856 A (often simply HD 30856[6]Cite error: The <ref> tag has too many names (see the help page).[7][8][a]
Since the star shares a very similar proper motion with HD 30856 A, the two stars are believed to be in a binary system. HD 30856 B revolves around the primary star (A) in a wide orbit, with a semi-major axis of 93 ± 8 AU.[4]
Nomenclature
In 2019, the People's Republic of Burkina Faso was assigned to giving the HD 30856 A system a proper name as part of the IAU100 NameExoWorlds Project,[2] planned to celebrate the hundredth anniversary of the International Astronomical Union (IAU), which grants the right to name an exoplanetary system to every state and territory in the world. Names were submitted and selected within Burkina Faso, which were then presented to the IAU to be officially recognized.[9] On 17 December 2019, the IAU announced that HD 30856 A and its planet, b, were named Mouhoun and Nakanbé, respectively.[10]
Mouhoun is named after the Black Volta (locally called Mouhoun), Burkina Faso's largest river that serves a crucial societal role in the western part of the country. Nakanbé is the native name for the White Volta, the second largest river in the nation with its source located in the Sahel region.[10]
Planetary system
In 2011, radial-velocity observations made at the W. M. Keck Observatory revealed the existence of one exoplanet around HD 30856 A.[6] The planet, HD 30856 Ab, is thought to be a gas giant at least 1.5 times the mass of Jupiter, which orbits its host star at a distance of 1.85 AU once every 847 days (2.32 years).[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| HD 30856 Ab (Nakanbé) | >1.547 MJ | 1.85 | 847.468 ± 19.811 | 0.061 ± 0.058 | — | 1.228 RJ |
References
- ^ a b c d e f g h i j k l "HD 30856". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2024-07-30.
- ^ a b "List of stars and planets". Name ExoWorlds. IAU. Retrieved 2019-09-15.
- ^ a b c ESA (1997), The HIPPARCOS and TYCHO catalogues. Astrometric and photometric star catalogues derived from the ESA HIPPARCOS Space Astrometry Mission, ESA SP Series, vol. 1200, Noordwijk, Netherlands: ESA Publications Division, Bibcode:1997ESASP1200.....E, ISBN 9290923997
- ^ a b c d e f g Ngo, Henry; Knutson, Heather A.; Bryan, Marta L.; Blunt, Sarah; Nielsen, Eric L.; Batygin, Konstantin; Bowler, Brendan P.; Crepp, Justin R.; Hinkley, Sasha; Howard, Andrew W.; Mawet, Dimitri (2017-06-01). "No Difference in Orbital Parameters of RV-detected Giant Planets between 0.1 and 5 au in Single versus Multi-stellar Systems". The Astronomical Journal. 153 (6): 242. doi:10.3847/1538-3881/aa6cac. ISSN 0004-6256.
- ^ a b c d e f Luhn, Jacob K.; Bastien, Fabienne A.; Wright, Jason T.; Johnson, John A.; Howard, Andrew W.; Isaacson, Howard (2019-04-01). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4): 149. doi:10.3847/1538-3881/aaf5d0. ISSN 0004-6256.
- ^ a b c d e Johnson, John Asher; Clanton, Christian; Howard, Andrew W.; Bowler, Brendan P.; Henry, Gregory W.; Marcy, Geoffrey W.; Crepp, Justin R.; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Wright, Jason T.; Isaacson, Howard (2011-12-01). "RETIRED A STARS AND THEIR COMPANIONS. VII. 18 NEW JOVIAN PLANETS". The Astrophysical Journal Supplement Series. 197 (2): 26. doi:10.1088/0067-0049/197/2/26. ISSN 0067-0049.
- ^ Mamajek, Eric (2 March 2021). "A Modern Mean Dwarf Stellar Color and Effective Temperature Sequence". University of Rochester, Department of Physics and Astronomy. Retrieved 5 July 2021.
- ^ Cifuentes, C.; Caballero, J.A.; Cortés-Contreras, M.; Montes, D.; Abellán, F.J.; Dorda, R.; Holgado, G. (2020). "CARMENES input catalogue of M dwarfs. V. Luminosities, colours, and spectral energy distributions". Astronomy and Astrophysics. 642 (October 2020): 32. arXiv:2007.15077. Bibcode:2020A&A...642A.115C. doi:10.1051/0004-6361/202038295.
- ^ "Methodology". Name ExoWorlds. IAU. Retrieved 2019-09-15.
- ^ a b "Approved names" (PDF). NameExoWorlds. IAU. p. 4. Retrieved 2024-07-30.
Footnotes
- ^ According to the listed sources, typical M0V and M1V stars have masses of 0.57 / 0.54 M☉ and surface temperatures of 3850 / 3660 K, respectively.
See also
- List of proper names of stars
- List of proper names of exoplanets
- List of stars in Eridanus
- List of exoplanets discovered in 2011
External links
- HD 30856 - NASA Exoplanet Archive
- Planet HD 30856 A b - Extrasolar Planets Encyclopaedia
- HD 30856 b - Exoplanets Data Explorer
- Burkina Faso | IAU100 Name ExoWorlds
Category:Eridanus (constellation) Category:Planetary systems Category:Stars