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, it is located 87.44 light-years away. The star appears to be moving further from the Earth with a heliocentric radial velocity of +1.9 km/s.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Apus |
| Right ascension | 15h 15m 15.04464s[1] |
| Declination | −70° 31′ 10.6449″[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) | +1.94±0.12[1] km/s |
| Proper motion (μ) | RA: −177.871 mas/yr[1] Dec.: −164.709 mas/yr[1] |
| Parallax (π) | 37.3020 ± 0.0182 mas[1] |
| Distance | 87.44 ± 0.04 ly (26.81 ± 0.01 pc) |
| Absolute magnitude (MV) | 4.74[2] |
| Details[4] | |
| Mass | 1.046+0.070 −0.059 M☉ |
| Radius | 1.158+0.039 −0.036 R☉ |
| Luminosity | 1.161+0.071 −0.049 L☉ |
| Surface gravity (log g) | 4.330+0.044 −0.041 cgs |
| Temperature | 5,576+86 −85 K |
| Metallicity [Fe/H] | +0.343+0.081 −0.084 dex |
| Rotation | 42.0±3.9 d |
| Age | 7.3+3.6 −3.4 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.[6] It has about the same[7] mass as the Sun but is 25% more luminous.[2] The photosphere is radiating energy at an effective temperature of 5,614 K.[7] It has a higher than solar metallicity – a term astronomers use to describe the abundance of elements other than hydrogen and helium.[7]
There is a companion star of spectral type M3V at a separation of ~1500 AU, designated L 72-1.[8][4] This companion presents a bimodal distribution of the Gaia DR3 G-band light-curve, indicating that it is a close binary.[9]
Planetary system
editThe 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.[10] None of the planetary orbits displays a mean motion resonance with the others.[11]
The system was updated by a 2024 study, which confirmed the three previously reported planets, though with a longer period for planet d, and detected two new ones. While all five planets are very likely to be real, the study advises caution regarding planet f due to the similarity of its period to the lunar cycle. The five planets range from super-Earth to super-Neptune mass, and the outermost, HD 134606 d, is a small gas giant orbiting within the habitable zone that may be a candidate for future space-based direct imaging missions. A long-period radial velocity trend was also detected, suggesting the presence of a distant sixth substellar companion of some kind.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| e | ≥2.34+0.35 −0.34 M🜨 |
0.0527+0.0011 −0.0012 |
4.3203+0.00051 −0.00047 |
0.2+0.14 −0.13 |
— | — |
| b | ≥9.09+0.64 −0.63 M🜨 |
0.1046+0.0023 −0.0024 |
12.089+0.0016 −0.0015 |
0.092+0.054 −0.053 |
— | — |
| f | ≥5.63+0.72 −0.69 M🜨 |
0.1784+0.0039 −0.0041 |
26.915±0.016 | 0.081+0.1 −0.059 |
— | — |
| c | ≥11.31+1.0 −0.99 M🜨 |
0.3007+0.0066 −0.0069 |
58.883+0.041 −0.039 |
0.055+0.062 −0.04 |
— | — |
| d | ≥44.8±2.9 M🜨 | 1.941+0.043 −0.046 |
966.5+5.3 −6.9 |
0.092±0.045 | — | — |
References
edit- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e 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.
- ^ a b 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.
- ^ a b c d Li, Zhexing; Kane, Stephen R.; Brandt, Timothy D.; Fetherolf, Tara; Robertson, Paul; Zhao, Jinglin; Dalba, Paul A.; Wittenmyer, Robert A.; Butler, R. Paul (April 2024). "Revised Architecture and Two New Super-Earths in the HD 134606 Planetary System". The Astronomical Journal. 167 (4): 155. arXiv:2401.17415. Bibcode:2024AJ....167..155L. doi:10.3847/1538-3881/ad2461.
- ^ "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.
- ^ a b c 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.
- ^ "L 72-1". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 1 February 2024.
- ^ González-Payo, J.; Caballero, J. A.; Gorgas, J.; Cortés-Contreras, M.; Gálvez-Ortiz, M.-C.; Cifuentes, C. (2024-07-29). "Multiplicity of stars with planets in the solar neighbourhood". arXiv:2407.20138 [astro-ph.SR].
- ^ 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
- ^ 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