HD 128311

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HD 128311
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
Right ascension 14h 36m 00.56s[1]
Declination +09° 44′ 47.5″[1]
Apparent magnitude (V) 7.51
Characteristics
Spectral type K0V
U−B color index 0.78
B−V color index 0.99
Variable type Variable star
HN Boo
Astrometry
Radial velocity (Rv) -9.6 ± 0.4 km/s
Proper motion (μ) RA: 204.74 ± 0.74[1] mas/yr
Dec.: -249.98 ± 0.61[1] mas/yr
Parallax (π) 60.60 ± 0.83[1] mas
Distance 53.8 ± 0.7 ly
(16.5 ± 0.2 pc)
Absolute magnitude (MV) 8.5
Details
Mass 0.8 M
Radius 0.73 R
Luminosity 0.221 L
Surface gravity (log g) 41.9 g cgs
Temperature 4965 K
Metallicity 108%
Age 0.39 Gyr
Equatorial [ g ] 411 m/s2
Other designations
BD+10°2710, GC 19679, GJ3860, GSC 00910-00165, HIP 71395, HN Boötis, LTT 14312, SAO 120554.
Database references
SIMBAD data
ARICNS data
Data sources:
Hipparcos Catalogue,
CCDM (2002),
Bright Star Catalogue (5th rev. ed.)

HD 128311 or HN Boötis is an orange main-sequence star located approximately 54 light-years away in the constellation of Boötes. Two extrasolar planet candidates have been detected in orbit around this star.

Planetary system[edit]

In 2002, the discovery of the planet HD 128311 b was announced by Paul Butler.[2] In 2005, the discovery of a second planet HD 128311 c was announced by Steve Vogt.[3]

Most likely, the system has been formed in a very turbulent disc.[4] The authors were able to show with both analytic and numerical models that certain libration modes are readily excited by turbulence. It was initially thought that the system could have been resulted from planet planet scattering, but this is rather unlikely.

Time evolution of orbital elements in the system HD128311. This left panel in this plot shows the most likely formation scenario for the planetary system. The right panel shows the observed orbital configuration.
Time evolution of orbital elements in the system HD128311. This left panel in this plot shows the most likely formation scenario for the planetary system. The right panel shows the observed orbital configuration.
The HD 128311 planetary system[3]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b >2.18 ± 0.22 MJ 1.099 ± 0.04 458.6 ± 6.8 0.25 ± 0.10
c >3.21 ± 0.30 MJ 1.76 ± 0.13 928.3 ± 18 0.17 ± 0.09

See also[edit]

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. ^ Butler, R. Paul et al. (2003). "Seven New Keck Planets Orbiting G and K Dwarfs". The Astrophysical Journal 582 (1): 455–466. Bibcode:2003ApJ...582..455B. doi:10.1086/344570. 
  3. ^ a b Vogt, Steven S. et al. (2005). "Five New Multicomponent Planetary Systems". The Astrophysical Journal 632 (1): 638–658. Bibcode:2005ApJ...632..638V. doi:10.1086/432901. 
  4. ^ Rein, Hanno; Papaloizou, J. C. B. (2009). "On the evolution of mean motion resonances through stochastic forcing: Fast and slow libration modes and the origin of HD128311". Astronomy and Astrophysics 497: 595–609. arXiv:0811.1813. Bibcode:2009A&A...497..595R. doi:10.1051/0004-6361/200811330. 

External links[edit]

Coordinates: Sky map 14h 36m 00.5607s, +09° 44′ 47.466″