HD 164427
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Pavo |
Right ascension | 18h 04m 42.58968s[1] |
Declination | −59° 12′ 34.4678″[1] |
Apparent magnitude (V) | 6.88[2] |
Characteristics | |
Spectral type | G0+V[3] |
B−V color index | ±0.015 0.624[2] |
Astrometry | |
Radial velocity (Rv) | ±0.25 +3.40[1] km/s |
Proper motion (μ) | RA: −196.087[1] mas/yr Dec.: −51.219[1] mas/yr |
Parallax (π) | 23.4516 ± 0.1836[1] mas |
Distance | 139 ± 1 ly (42.6 ± 0.3 pc) |
Absolute magnitude (MV) | ±0.06 3.98[4] |
Details | |
Mass | +0.063 −0.024 1.125[5] M☉ |
Radius | +0.05 −0.06 1.40[5] R☉ |
Luminosity | 2.33[2] L☉ |
Surface gravity (log g) | +0.03 −0.04 4.24[5] cgs |
Temperature | 5,876[3] K |
Metallicity [Fe/H] | ±0.03 0.11[6] dex |
Age | +1.3 −0.9 6.6[4] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 164427 is a star with a brown dwarf companion in the southern constellation of Pavo. It has an apparent visual magnitude of 6.88,[2] placing it just below the nominal limit for visibility with the typical naked eye. The annual parallax shift of mas 23.5[1] yields a distance estimate of 42.6 light years. It is moving further from the Earth with a heliocentric radial velocity of +3.4 km/s.[1]
This is an inactive[8] G-type main-sequence star given a stellar classification of G0+V by Gray et al. (2006),[3] although Evans et al. (1964) classified it as a subgiant star with luminosity class IV.[8] It is 6.6 billion years old with 1.125 times the mass of the Sun and 1.40 times the Sun's radius.[5] The star is somewhat over-luminous for its class,[8] radiating 2.33[2] times the Sun's luminosity from its photosphere at an effective temperature of 5,876 K.[3]
In 2001, a brown dwarf candidate companion was announced by Anglo-Australian Planet Search program. It was detected by the Doppler velocity technique with an echelle spectrograph attached to the 3.92m Anglo-Australian Telescope.[8] A magnitude 12.60 companion star designated HD 164427 B lies at an angular separation of ″ along a 28.90position angle of 336°, as of 2010.[9] This is a suspected common proper motion companion with 52% of the Sun's mass[10] and a physical separation of as much as AU. 1,090[8]
HD 164427 b
Exoplanet | List of exoplanets | |
---|---|---|
Orbital elements | ||
Semi-major axis | (a) | 0.46 AU |
Eccentricity | (e) | 0.55 |
Orbital period | (P) | 108.55 d |
Argument of periastron |
(ω) | 55.2° |
Time of periastron | (T0) | 2,451,189.3 JD |
Semi-amplitude | (K) | 1398.5 m/s |
Physical characteristics | ||
Mass | (m) | >46 MJ |
Radius | (r) | >1.4 RJ |
Discovery information | ||
Discovery date | 2001 | |
Discoverer(s) | Tinney et al. | |
Discovery method | Doppler Spectroscopy | |
Discovery site | Australia | |
Discovery status | Published |
HD 164427 b is a brown dwarf with a minimum mass of 46 times that of Jupiter. It orbits at nearly half an astronomical unit or Earth-to-Sun distance away from its star (HD 164427). The angular separation between a brown dwarf and a yellow dwarf as viewed from Earth is 11.76 Milliarcseconds. It takes 108.55 Earth days to orbit eccentrically around HD 164427. It has a very high semi-amplitude of almost 1400 m/s, because this is a very massive object which exerts strong gravitational pull on its tugging star.[8]
References
- 1 2 3 4 5 6 7 8 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.
- 1 2 3 4 5 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.
- 1 2 3 4 Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637.
- 1 2 Holmberg, J.; et al. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics Supplement Series. 501 (3): 941–947. arXiv:0811.3982. Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191.
- 1 2 3 4 Takeda, Genya; et al. (February 2007). "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog". The Astrophysical Journal Supplement Series. 168 (2): 297–318. arXiv:astro-ph/0607235. Bibcode:2007ApJS..168..297T. doi:10.1086/509763.
- ↑ Gáspár, András; et al. (August 2016). "The Correlation between Metallicity and Debris Disk Mass". The Astrophysical Journal. 826 (2): 14. arXiv:1604.07403. Bibcode:2016ApJ...826..171G. doi:10.3847/0004-637X/826/2/171. 171.
- ↑ "HD 164427". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-08-02.
- 1 2 3 4 5 6 Tinney, C. G.; et al. (2001). "First Results from the Anglo-Australian Planet Search: A Brown Dwarf Candidate and a 51 Peglike Planet". The Astrophysical Journal. 551 (1): 507–511. arXiv:astro-ph/0012204. Bibcode:2001ApJ...551..507T. doi:10.1086/320097.
- ↑ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
- ↑ Tokovinin, Andrei (April 2014). "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 14. arXiv:1401.6827. Bibcode:2014AJ....147...87T. doi:10.1088/0004-6256/147/4/87. 87.
External links
- "NLTT 45831 -- High proper-motion Star". SIMBAD. Retrieved December 21, 2007.