HD 154345

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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[edit]

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]

The HD 154345 planetary system[4]
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[edit]

  1. ^ a b c d e 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
  2. ^ a b c 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 
  3. ^ 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. 
  4. ^ a b c 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. 
  5. ^ "hd_154345_b". Extrasolar Planet Encyclopaedia. Retrieved November 12, 2012. 
  6. ^ 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. 
  7. ^ Square root of stellar luminosity.

External links[edit]

Coordinates: Sky map 17h 02m 36.40s, +47° 04′ 54.77″