HD 187123
| Observation data Epoch 2000 Equinox 2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 46m 58.1130s |
| Declination | +34° 25′ 10.288″ |
| Apparent magnitude (V) | 7.89 |
| Distance | 156.28 ly (47.92 pc) |
| Spectral type | G5V |
| Other designations | |
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HD 187123 has a planetary system with at least two planets in it. Artist's rendition of planets HD 187123b and c.
HD 187123 is an 8th magnitude G-type main sequence star located approximately 156 light-years away in the constellation of Cygnus. Like our Sun, it is a yellow dwarf (spectral type G5V). Being at a distance of about 160 light-years it is not visible to the unaided eye. However, it should be easy target with binoculars or small telescope.
Planetary system
In 1998 the California and Carnegie Planet Search team, after following a suggestion by Kevin Apps, a Briton who at the time was an undergraduate student[1] found a possible planet orbiting the star.[2] There were also indications of another, more distant body orbiting the star and this claim was published in 2006.[3] This planet was confirmed in 2009.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.523 ± 0.043 MJ | 0.0426 ± 0.0025 | 3.0965828 ± 0.0000078 | 0.0103 ± 0.0059 | — | — |
| c | ≥ 1.99 ± 0.25 MJ | 4.89 ± 0.53 | 3810 ± 420 | 0.252 ± 0.033 | — | — |
See also
References
- ↑ "British student shows Nasa new planet". BBC News. September 25, 1998. Retrieved December 31, 2011.
- ↑ Butler, R. Paul; et al. (1998). "A Planet with a 3.1 Day Period around a Solar Twin". Publications of the Astronomical Society of the Pacific 110 (754): 1389–1393. Bibcode:1998PASP..110.1389B. doi:10.1086/316287.
- ↑ 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. arXiv:astro-ph/0611658. Bibcode:2007ApJ...657..533W. doi:10.1086/510553.
- 1 2 Wright, J. T.; et al. (2009). "Ten New and Updated Multi-planet Systems, and a Survey of Exoplanetary Systems". The Astrophysical Journal 693 (2): 1084–1099. arXiv:0812.1582. Bibcode:2009ApJ...693.1084W. doi:10.1088/0004-637X/693/2/1084.
External links
- "Notes for star HD 187123". The Extrasolar Planets Encyclopaedia. Retrieved 2008-08-25.
Coordinates: 
19h 46m 58.1130s, +34° 25′ 10.288″
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