HD 134606
HD 134606 is a yellow-hued star with a planetary system, positioned in the southern constellation of Apus. It is below the nominal limit for visibility with the naked eye, having an apparent visual magnitude of 6.86.[2] Based upon an annual parallax shift of 37.3 mas,[1] it is located 87.45 light years away. The star appears to be moving further from the Earth with a heliocentric radial velocity of +2.3 km/s.[4]
| Observation data Epoch J2000 Equinox J2000  | |
|---|---|
| Constellation | Apus | 
| Right ascension | 15h 15m 15.04429s[1] | 
| Declination | −70° 31′ 10.6439″[1] | 
| Apparent magnitude (V) | 6.86[2] | 
| Characteristics | |
| Spectral type | G6 IV[3] | 
| B−V color index | 0.740±0.001[2] | 
| Astrometry | |
| Radial velocity (Rv) | +2.30±1.21[4] km/s | 
| Proper motion (μ) |  RA: −177.748[1] mas/yr  Dec.: −164.774[1] mas/yr  | 
| Parallax (π) | 37.2972 ± 0.0283 mas[1] | 
| Distance | 87.45 ± 0.07 ly  (26.81 ± 0.02 pc)  | 
| Absolute magnitude (MV) | 4.74[2] | 
| Details[5] | |
| Mass | 0.998±0.024 M☉ | 
| Luminosity | 1.25[2] L☉ | 
| Surface gravity (log g) | 4.30±0.08 cgs | 
| Temperature | 5,614±34 K | 
| Metallicity [Fe/H] | +0.27±0.03 dex | 
| Age | 4.349±2.399 Gyr | 
| Other designations | |
| Database references | |
| SIMBAD | data | 
This is an evolving G-type subgiant star with a stellar classification of G6 IV[3] and is not considered active, having a chromospheric activity index of −5.04.[7] It has about the same[5] mass as the Sun but is 25% more luminous.[2] The photosphere is radiating energy at an effective temperature of 5,614 K.[5] It has a higher than solar metallicity rating – a term astronomers use to describe the abundance of elements other than hydrogen and helium.[5]
Planetary system
    
The discovery of a planetary system orbiting HD 134606 was announced in 2011 following an eight-year survey carried out at the La Silla Observatory in Chile. The detection was made via the radial velocity method using the HARPS instrument. Applying a Keplerian fit to the data suggests the presence of three planets in moderately eccentric orbits.[8] The planets are successively larger the further away they are from the star.[9] None of the planetary orbits displays a mean motion resonance with the others.[10]
| Companion (in order from star)  | 
Mass | Semimajor axis (AU)  | 
Orbital period (days)  | 
Eccentricity | Inclination | Radius | 
|---|---|---|---|---|---|---|
| b | ≥ 9.28±0.95 M🜨 | 0.1023±0.0017 | 12.083±0.0096 | 0.15±0.1 | — | — | 
| c | ≥ 12.14±1.52 M🜨 | 0.2962±0.0049 | 59.519±0.1746 | 0.29±0.2 | — | — | 
| d | ≥ 38.45±4.13 M🜨 | 1.1567±0.0241 | 459.26±8.3238 | 0.46±0.09 | — | — | 
References
    
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
 - Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
 - Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
 - de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61
 - Tsantaki, M.; et al. (July 2013). "Deriving precise parameters for cool solar-type stars. Optimizing the iron line list". Astronomy & Astrophysics. 555: A150. arXiv:1304.6639. Bibcode:2013A&A...555A.150T. doi:10.1051/0004-6361/201321103. S2CID 118388752.
 - "HD 134606". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 20, 2018.
 - Jenkins, J. S.; et al. (October 2006), "An activity catalogue of southern stars", Monthly Notices of the Royal Astronomical Society, 372 (1): 163–173, arXiv:astro-ph/0607336, Bibcode:2006MNRAS.372..163J, doi:10.1111/j.1365-2966.2006.10811.x, S2CID 17524675.
 - Mayor, M.; Marmier, M.; Lovis, C.; Udry, S.; Ségransan, D.; Pepe, F.; Benz, W.; Bertaux, J.-L.; Bouchy, F.; Dumusque, X.; Lo Curto, G.; Mordasini, C.; Queloz, D.; Santos, N. C. (September 13, 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
 - Schlaufman, Kevin C. (2014). "Tests of in situ Formation Scenarios for Compact Multiplanet Systems". The Astrophysical Journal. 790 (2): 11. arXiv:1402.7075. Bibcode:2014ApJ...790...91S. doi:10.1088/0004-637X/790/2/91. S2CID 8130257. 91.
 - Giuppone, C. A.; et al. (December 2013), "A semi-empirical stability criterion for real planetary systems with eccentric orbits", Monthly Notices of the Royal Astronomical Society, 436 (4): 3547–3556, arXiv:1309.6861, Bibcode:2013MNRAS.436.3547G, doi:10.1093/mnras/stt1831
 - "HD 134606", Extrasolar Planet Encyclopaedia, retrieved 2015-09-20