astro.wikisort.org - StarKepler-18 is a star with almost the same mass as the Sun in the Cygnus constellation
Star in the constellation Cygnus
Kepler-18
Observation data
Epoch J2000 Equinox J2000 |
| Constellation |
Cygnus |
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| Right ascension |
19h 52m 19.0688s[1] |
| Declination |
+44° 44′ 46.808″[1] |
| Apparent magnitude (V) |
14.0 |
| Characteristics |
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| Spectral type |
G7 |
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| Astrometry |
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| Proper motion (μ) | RA: −1.432±0.031[1] mas/yr
Dec.: −20.313±0.028[1] mas/yr |
| Parallax (π) | 2.2804 ± 0.0168 mas[1] |
| Distance | 1,430 ± 10 ly
(439 ± 3 pc) |
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| Details[2] |
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| Mass | 0.972 ± 0.042 M☉ |
| Radius | 1.108 ± 0.051 R☉ |
| Luminosity | 0.93 L☉ |
| Surface gravity (log g) | 4.32 ± 0.12 cgs |
| Temperature | 5383 ± 44 K |
| Metallicity [Fe/H] | 0.19 ± 0.06 dex |
| Rotational velocity (v sin i) | <4 km/s |
| Age | 10.0 ± 2.3 Gyr |
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| Other designations |
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KOI-137, KIC 8644288,2MASS J19521906+4444467, Gaia DR2 2079295583282164992 [3] |
| Database references |
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| SIMBAD | data |
Extrasolar Planets
Encyclopaedia | data |
Planetary system
The star is orbited by 3 confirmed planets, announced in 2011.[2] In 2021, it was found the orbital plane of Kepler-18d is slowly changing, likely under the gravitational influence of the additional giant planet.[4]
The Kepler-18 planetary system[2][5]
Companion
(in order from star) |
Mass |
Semimajor axis
(AU) |
Orbital period
(days) |
Eccentricity |
Inclination |
Radius |
| b |
6.9 ± 3.4 M🜨 |
0.0447 ± 0.0006 |
3.504725 ± 0.000028 |
— |
84.92 ± 0.26° |
2.00 ± 0.10 R🜨 |
| c |
17.3 ± 1.9 M🜨 |
0.0752 ± 0.0011 |
7.6415716 |
— |
87.68 ± 0.22° |
5.49 ± 0.26 R🜨 |
| d |
16.4 ± 1.4 M🜨 |
0.1172 ± 0.0017 |
14.858941 |
— |
88.07 ± 0.1° |
6.98 ± 0.33 R🜨 |
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia Data Release 2 catalog entry
- Cochran, William D.; et al. (2011). "Kepler 18-b, c, and d: A System Of Three Planets Confirmed by Transit Timing Variations, Lightcurve Validation, Spitzer Photometry and Radial Velocity Measurements". The Astrophysical Journal Supplement Series. 197: 7. arXiv:1110.0820. Bibcode:2011ApJS..197....7C. doi:10.1088/0067-0049/197/1/7. S2CID 16505452.
- "Kepler-18". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 25 January 2018.
- Systematic search for long-term transit duration changes in Kepler transiting planets, 2021, arXiv:2105.04318
- Montet, Benjamin T.; Johnson, John Asher (2013), "Model-Independent Stellar and Planetary Masses from Multi-Transiting Exoplanetary Systems", The Astrophysical Journal, 762 (2): 112, arXiv:1211.4028v1, doi:10.1088/0004-637X/762/2/112, S2CID 29261765
External links
На других языках
- [en] Kepler-18
[ru] Kepler-18
Kepler-18 — звезда в созвездии Лебедя. Находится на расстоянии около 1761 светового года от Солнца. Вокруг звезды обращаются, как минимум, три планеты.
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