| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 29m 10.98124s [1] |
| Declination | +11° 41′ 43.7985″ [1] |
| Apparent magnitude (V) | 8.21 [2] |
| Characteristics | |
| Spectral type | G5V + K5V [3] |
| B−V color index | 0.677±0.014 [2] |
| Astrometry | |
| Radial velocity (Rv) | −59.32±0.10 [3] km/s |
| Proper motion (μ) |
RA: −48.418±0.070
[1]
mas/
yr Dec.: −17.470±0.079 [1] mas/ yr |
| Parallax (π) | 16.5886 ± 0.0408 mas [1] |
| Distance | 196.6 ± 0.5
ly (60.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.23 [2] |
| Orbit [4] | |
| Primary | HD 170469 |
| Companion | HD 170469 B |
| Period (P) | 114000 yr |
| Semi-major axis (a) | 43.1″ |
| Details | |
| A | |
| Mass | 1.10 [5] M☉ |
| Radius | 1.24 [5] R☉ |
| Luminosity | 1.639±0.006 [1] L☉ |
| Surface gravity (log g) | 4.30±0.03 [5] cgs |
| Temperature | 5,786±28 [3] K |
| Metallicity [Fe/H] | 0.28±0.02 [3] dex |
| Age | 4.8+3.0 −0.5 [2] or 8.6±0.5 [6] Gyr |
| B | |
| Mass | 0.42 [7] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 170469 is a probable binary star [7] [4] system in the equatorial constellation of Ophiuchus. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.21. [2] The system is located at a distance of 197 light years away from the Sun based on parallax. It is drifting closer with a radial velocity of −59 km/s, [3] and is expected to come to within 49.8 light-years in about 959,000 years.
The primary, component A, is a G-type main-sequence star with a stellar classification of G5V, [3] indicating it is generating energy through core hydrogen fusion. Estimates of the star's age range from five [2] to almost nine [6] billion years. It has 1.10 times the mass of the Sun and 1.24 times the Sun's radius. [5] The star has a higher than solar metallicity. [3] It is radiating 1.64 [1] times the Sun's luminosity from its photosphere at an effective temperature of 5,786 K. [3]
The secondary companion, component B, is located at an angular separation of 43.21 ″±0.10 ″ along a position angle of 112.55°±0.07° from the primary, as of 2018. [3] Initially it was thought to be a red dwarf of spectral class M1, [4] but was later determined to be a K-type main-sequence star with a class of K5V. [3] This star lies at a projected separation of 2708 AU [4] from the primary, and is orbiting with an estimated period of around 114,000 years. [7]
Planetary system
In 2007, a planet was discovered by the N2K Consortium, led by principal investigators Debra Fischer and Gregory P. Laughlin. [9] It was spotted using the radial velocity method, and was independently confirmed in 2014. [4]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >0.67 MJ | 2.24 | 1,143 | 0.11 | — | — |
See also
References
- ^ a b c d e f g 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. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f 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 c d e f g h i j Montes, D.; et al. (September 2018). "Calibrating the metallicity of M dwarfs in wide physical binaries with F-, G-, and K-primaries - I: High-resolution spectroscopy with HERMES: stellar parameters, abundances, and kinematics". Monthly Notices of the Royal Astronomical Society. 479 (1): 1332–1382. arXiv: 1805.05394. Bibcode: 2018MNRAS.479.1332M. doi: 10.1093/mnras/sty1295. S2CID 119260219.
- ^ a b c d e Mugrauer, M.; et al. (March 2014). "New wide stellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 439 (1): 1063–1070. Bibcode: 2014MNRAS.439.1063M. doi: 10.1093/mnras/stu044.
- ^ a b c d Stassun, Keivan G.; et al. (2017). "Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes". The Astronomical Journal. 153 (3): 136. arXiv: 1609.04389. Bibcode: 2017AJ....153..136S. doi: 10.3847/1538-3881/aa5df3. S2CID 119219062.
- ^ a b Bonfanti, A.; et al. (March 2015). "Revising the ages of planet-hosting stars". Astronomy & Astrophysics. 575: 17. arXiv: 1411.4302. Bibcode: 2015A&A...575A..18B. doi: 10.1051/0004-6361/201424951. S2CID 54555839. A18.
- ^ a b c Tokovinin, Andrei (2014). "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 87. arXiv: 1401.6827. Bibcode: 2014AJ....147...87T. doi: 10.1088/0004-6256/147/4/87. S2CID 56066740.
- ^ "HD 170469". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
- ^ a b Fischer, Debra A.; et al. (2007). "Five Intermediate-Period Planets from the N2K Sample". The Astrophysical Journal. 669 (2): 1336–1344. arXiv: 0704.1191. Bibcode: 2007ApJ...669.1336F. doi: 10.1086/521869. S2CID 7774321.
