HD 154345
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 02m 36.404s[1] |
| Declination | +47° 04′ 54.76″[1] |
| Apparent magnitude (V) | +6.74 |
| Characteristics | |
| Spectral type | G8V |
| U−B color index | 0.27 |
| B−V color index | 0.73 |
| Variable type | none |
| Astrometry | |
| Radial velocity (Rv) | -46.2 km/s |
| Proper motion (μ) | RA: 123.27 ± 0.35[1] mas/yr Dec.: 853.63 ± 0.36[1] mas/yr |
| Parallax (π) | 53.80 ± 0.32[1] mas |
| Distance | 60.6 ± 0.4 ly (18.6 ± 0.1 pc) |
| Absolute magnitude (MV) | +5.46 |
| Details | |
| Mass | 0.88 M☉ |
| Luminosity | 0.568 L☉ |
| Temperature | 5468 ± 44 K |
| Metallicity | -0.105 ± 0.03 |
| Rotation | 27.8 ± 1.7 days[2] |
| Age | 4.92 ± 4.48 × 109 years |
| Other designations | |
HD 154345, BD+47º2420, GC 23011, GCRV 9834, Gliese 651, Gl 651, GJ 651, HIP 83389, SAO 46452 | |
HD 154345 (Gliese 651) is a G-type dwarf star located in northern Hercules. It is not visible to the naked eye since it is below +6.50 magnitude, but using binoculars it is an easy target.
Planetary system
In 2006, a long-period, wide-orbiting planet was observed by radial velocity, and published in May 2007, gaining the designation HD 154345 b.[3]
The complete observation of its nine-year orbit rules out any interior planets of minimum mass (m sini) greater than 0.3 Jupiter.[4] The star rotates at an inclination of 50+40
−26 degrees relative to Earth.[2] It is probable that the planet shares that inclination.[5][6] It has been called a "Jupiter twin".[4]
The system's habitable zone is centered at .754 AU and is narrower than the Sun's.[7]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.2+1.3 −0.4[2] MJ |
4.19 ± 0.26 | 9.15 ± 0.26 | 0.044 ± 0.046 | — | — |
References
- 1 2 3 4 5 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 - 1 2 3 Simpson, E. K.; et al. (November 2010), "Rotation periods of exoplanet host stars", Monthly Notices of the Royal Astronomical Society, 408 (3): 1666–1679, arXiv:1006.4121, Bibcode:2010MNRAS.408.1666S, doi:10.1111/j.1365-2966.2010.17230.x
- ↑ 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 3 Wright, J. T.; et al. (2008). "The Jupiter Twin HD 154345b". The Astrophysical Journal Letters. 683 (1): L63–L66. arXiv:0802.1731. Bibcode:2008ApJ...683L..63W. doi:10.1086/587461.
- ↑ "hd_154345_b". Extrasolar Planet Encyclopaedia. Retrieved November 12, 2012.
- ↑ Roberto Sanchis-Ojeda; Josh N. Winn; Daniel C. Fabrycky (2012). "Starspots and spin-orbit alignment for Kepler cool host stars". arXiv:1211.2002. Bibcode:2013AN....334..180S. doi:10.1002/asna.201211765.
- ↑ Square root of stellar luminosity.
External links
Coordinates: 
17h 02m 36.40s, +47° 04′ 54.77″