Astronomy:Zeta Horologii
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Horologium |
| Right ascension | 02h 40m 39.61286s[1] |
| Declination | −54° 32′ 59.6836″[1] |
| Apparent magnitude (V) | 5.20[2] |
| Characteristics | |
| Spectral type | F6 V[3] (F2 V + F5 V)[4] |
| B−V color index | +0.42[2] |
| Astrometry | |
| Radial velocity (Rv) | 5.8[3] km/s |
| Proper motion (μ) | RA: +32.86[1] mas/yr Dec.: +4.96[1] mas/yr |
| Parallax (π) | 20.37 ± 0.21[1] mas |
| Distance | 160 ± 2 ly (49.1 ± 0.5 pc) |
| Absolute magnitude (MV) | +1.76[5] |
| Orbit[4] | |
| Period (P) | 12.9274 d |
| Eccentricity (e) | 0.25 |
| Periastron epoch (T) | 7.361±0.046 |
| Argument of periastron (ω) (secondary) | 78.6±0.13° |
| Semi-amplitude (K1) (primary) | 58.1±1.37 km/s |
| Semi-amplitude (K2) (secondary) | 66.1±1.56 km/s |
| Details | |
| ζ Hor A | |
| Mass | 1.43[6] M☉ |
| Luminosity | 16.7[5] L☉ |
| Surface gravity (log g) | 3.74[7] cgs |
| Temperature | 6,702[7] K |
| Metallicity [Fe/H] | −0.07[7] dex |
| Rotational velocity (v sin i) | 8.0±1.2[3] km/s |
| Age | 1.50[7] Gyr |
| ζ Hor B | |
| Mass | 1.26[6] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Zeta Horologii, Latinized from ζ Horologii, is a yellow-white-hued binary star system in the southern constellation of Horologium. It is visible to the naked eye with a combined apparent visual magnitude of 5.20.[2] Based upon an annual parallax shift of 20.37 mas as seen from Earth,[1] it is located around 160 light-years from the Sun.
This system was determined to be a double-lined spectroscopic binary by J. H. Moore in 1911−12. The first orbital elements were published by J. Sahade and C. A. Hernández in 1964, who found it consisted of two F-type main-sequence stars of probable stellar classifications F2 V and F5 V. The pair orbit each other with a period of 12.9274 days and an eccentricity of 0.25.[4] The system displays an infrared excess at a wavelength of 24 μm but not at 70 μm, yielding a derived temperature of 260 K. This suggests a circumbinary debris disk orbiting at a distance of less than 4.8 AU from the star system.[9]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa 27: 11, Bibcode: 1968MNSSA..27...11C.
- ↑ 3.0 3.1 3.2 Torres, C. A. O. et al. (December 2006), "Search for associations containing young stars (SACY). I. Sample and searching method", Astronomy and Astrophysics 460 (3): 695–708, doi:10.1051/0004-6361:20065602, Bibcode: 2006A&A...460..695T.
- ↑ 4.0 4.1 4.2 Sahade, J.; Hernández, C. A. (February 1964), "The spectroscopic binary ζ Horologii", Annales d'Astrophysique 27: 11, Bibcode: 1964AnAp...27...11S.
- ↑ 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 Tokovinin, A. et al. (May 2006), "Tertiary companions to close spectroscopic binaries", Astronomy and Astrophysics 450 (2): 681–693, doi:10.1051/0004-6361:20054427, Bibcode: 2006A&A...450..681T.
- ↑ 7.0 7.1 7.2 7.3 Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C.
- ↑ "zet Hor -- Spectroscopic binary", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=zet+Hor, retrieved 2017-04-25.
- ↑ Trilling, D. E. et al. (April 2007), "Debris disks in main-sequence binary systems", The Astrophysical Journal 658 (2): 1264–1288, doi:10.1086/511668, Bibcode: 2007ApJ...658.1289T.
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