HD 20781
HD 20781 is a star which is part of a wide binary system with HD 20782. The companion star has a very large angular separation of 252 arcsec, corresponding to 9080 AU at the distance of HD 20782.[4] Both stars possess their own planetary systems in S type orbits. This is the first time that planets have been found in both components of a wide binary system.[4][5][6]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Fornax[1] |
| Right ascension | 03h 20m 02.943s[2] |
| Declination | –28° 47′ 01.80″[2] |
| Apparent magnitude (V) | 8.44 |
| Characteristics | |
| Spectral type | G9.5V |
| Astrometry | |
| Proper motion (μ) | RA: 348.97 ± 0.71[2] mas/yr Dec.: –67.69 ± 0.91[2] mas/yr |
| Parallax (π) | 28.27 ± 1.08[2] mas |
| Distance | 115 ± 4 ly (35 ± 1 pc) |
| Other designations | |
| Database references | |
| SIMBAD | data |
Planetary system
HD 20781
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 12.04 ± 1.11 M⊕ | 0.169 ± 0.0028 | 29.15 ± 0.0201 | 0.11 ± 0.06 | — | — |
| c | 15.76 ± 1,20 M⊕ | 0.3456 ± 0.0047 | 85.131 ± 0.1161 | 0.28 ± 0.09 | — | — |
See also
- List of extrasolar planets
- XO-2, a wide binary star in the constellation Lynx
References
- Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
- van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.Vizier catalog entry
- "HD 20781 -- High proper-motion Star". SIMBAD Astronomical Database. Centre de données astronomiques de Strasbourg. Retrieved 2014-09-10.
- Properties of planets in binary systems.
- Schneider, J. "Notes for star HD 20781". The Extrasolar Planets Encyclopaedia. Retrieved 2011-09-12.
- Mayor, M. Marmier,M. Lovis,C. Udry,S. Ségransan,D. Pepe,F. Benz,W. Bertaux,J.-L. Bouchy,F. Dumusque, G. Curto,Lo Mordasini,C. Queloz,D. Santos,N. C.; et al. (2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets". arXiv:1109.2497 [astro-ph].CS1 maint: multiple names: authors list (link)
External links
- "Notes for star HD 20781". The Extrasolar Planets Encyclopaedia. Retrieved 2011. Check date values in:
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