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 mas [1] |
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]