Astronomy:HD 208487
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Grus[1] |
| Right ascension | 21h 57m 19.84754s[2] |
| Declination | −37° 45′ 49.0480″[2] |
| Apparent magnitude (V) | 7.47[1] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | G1/3V[3] |
| B−V color index | 0.568±0.009[1] |
| Variable type | Stable[4] |
| Astrometry | |
| Radial velocity (Rv) | 5.575±0.0004[5] km/s |
| Proper motion (μ) | RA: 101.032[2] mas/yr Dec.: −118.842[2] mas/yr |
| Parallax (π) | 22.2688 ± 0.0304[2] mas |
| Distance | 146.5 ± 0.2 ly (44.91 ± 0.06 pc) |
| Absolute magnitude (MV) | 4.26[4] |
| Absolute bolometric magnitude (Mbol) | 4.06[4] |
| Details | |
| Mass | 1.16±0.02[6] M☉ |
| Radius | 1.17±0.03[6] R☉ |
| Luminosity | 1.76±0.05[6] L☉ |
| Surface gravity (log g) | 4.36±0.03[6] cgs |
| Temperature | 6,143±47[6] K |
| Metallicity [Fe/H] | 0.08[7] dex |
| Rotational velocity (v sin i) | 3.688[6] km/s |
| Age | 2.3±0.9 Gyr[6] 1.325±1.007[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 208487 is a star with an orbiting exoplanet in the constellation of Grus. Based on parallax measurements, it is located at a distance of 146.5 light years from the Sun. The absolute magnitude of HD 208487 is 4.26,[4] but at that distance the apparent visual magnitude is 7.47,[1] which is too faint to be viewed with the naked eye. The system is drifting further away with a radial velocity of 5.6 km/s.[5] It is a member of the thin disk population.[7]
The spectrum of HD 208487 presents as an ordinary G-type main-sequence star with a stellar classification of G1/3V.[3] It is a relatively young star, with age estimates of 1–2 billion years, and is spinning with a projected rotational velocity of 3.7 km/s.[7][6] The star has 16% greater mass and a 17% larger radius than the Sun.[6] The abundance of iron, a measure of the star's metallicity, is similar to the Sun.[7] It is radiating 176% of the luminosity of the Sun from its photosphere at an effective temperature of 6,143 K.[6] The level of magnetic activity in the chromosphere is low.[4]
The star HD 208487 is named Itonda and the exoplanet Mintome. The names were selected in the NameExoWorlds campaign by Gabon, during the 100th anniversary of the IAU. Itonda, in the Myene tongue, corresponds to all that is beautiful. Mintome, in the Fang tongue, is a mythical land where a brotherhood of brave men live.[9][10]
Planetary system
There is one known planet orbiting the star HD 208487, which is designated HD 208487 b.[4] It has a mass at least half that of Jupiter and is located in an eccentric 130-day orbit.
The discovery of a second planet in the system was announced on 13 September 2005, by P.C. Gregory. The discovery was made using Bayesian analysis of the radial velocity dataset to determine the planetary parameters.[11] However, further analysis revealed that an alternative two-planet solution for the HD 208487 system was possible, with a planet in a 28-day orbit instead of the 908-day orbit postulated, and it was concluded that activity on the star is more likely to be responsible for the residuals to the one-planet solution than the presence of a second planet.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Mintome | >0.520 ± 0.082 MJ | 0.51 ± 0.02 | 130.08 ± 0.51 | 0.24 ± 0.16 | — | — |
See also
References
- ↑ 1.0 1.1 1.2 1.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 Houk, Nancy (1982). Michigan catalogue of two-dimensional spectral types for the HD stars. 3. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode: 1982mcts.book.....H.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Tinney, C. G. et al. (2005). "Three Low-Mass Planets from the Anglo-Australian Planet Search". The Astrophysical Journal 623 (2): 1171–1179. doi:10.1086/428661. Bibcode: 2005ApJ...623.1171T.
- ↑ 5.0 5.1 Soubiran, C. et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics 616: A7. doi:10.1051/0004-6361/201832795. Bibcode: 2018A&A...616A...7S.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 Bonfanti, A. et al. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics 585: 14. doi:10.1051/0004-6361/201527297. A5. Bibcode: 2016A&A...585A...5B.
- ↑ 7.0 7.1 7.2 7.3 7.4 Costa Silva, A. R. et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics 634: 10. doi:10.1051/0004-6361/201936523. A136. Bibcode: 2020A&A...634A.136C.
- ↑ "HD 208487". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+208487.
- ↑ "Approved names" (in en). http://www.nameexoworlds.iau.org/final-results.
- ↑ "International Astronomical Union | IAU". https://www.iau.org/news/pressreleases/detail/iau1912/.
- ↑ Gregory, P.C. (2007). "A Bayesian Kepler periodogram detects a second planet in HD 208487". Monthly Notices of the Royal Astronomical Society 374 (4): 1321–1333. doi:10.1111/j.1365-2966.2006.11240.x. Bibcode: 2007MNRAS.374.1321G.
- ↑ Wright, J.T. et al. (2007). "Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars". The Astrophysical Journal 657 (1): 533–545. doi:10.1086/510553. Bibcode: 2007ApJ...657..533W.
External links
- "Notes for star HD 208487". Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=HD+208487. Retrieved 2008-08-29.
Coordinates: 
21h 57m 19.8477s, −37° 45′ 49.037″
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