Zeta Horologii
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.
Observation data Epoch J2000.0 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 |
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 24μm but not at 70μm, 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
- van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- 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.
- 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, arXiv:astro-ph/0609258, Bibcode:2006A&A...460..695T, doi:10.1051/0004-6361:20065602.
- Sahade, J.; Hernández, C. A. (February 1964), "The spectroscopic binary ζ Horologii", Annales d'Astrophysique, 27: 11, Bibcode:1964AnAp...27...11S.
- 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.
- Tokovinin, A.; et al. (May 2006), "Tertiary companions to close spectroscopic binaries", Astronomy and Astrophysics, 450 (2): 681–693, arXiv:astro-ph/0601518, Bibcode:2006A&A...450..681T, doi:10.1051/0004-6361:20054427.
- 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, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276.
- "zet Hor -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, 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, arXiv:astro-ph/0612029, Bibcode:2007ApJ...658.1289T, doi:10.1086/511668.