Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ophiuchus |
Right ascension | 17h 21m 00.37452s [1] |
Declination | −21° 06′ 46.5710″ [1] |
Apparent magnitude (V) | 4.39 [2] |
Characteristics | |
Spectral type | F2V [3] |
U−B color index | -0.06 [4] |
B−V color index | +0.41 [4] |
Astrometry | |
Radial velocity (Rv) | −8.73±0.12 [1] km/s |
Proper motion (μ) |
RA: +265.543
mas/
yr
[1] Dec.: -202.584 mas/ yr [1] |
Parallax (π) | 57.0820 ± 0.1851 mas [1] |
Distance | 57.1 ± 0.2
ly (17.52 ± 0.06 pc) |
Absolute magnitude (MV) | 3.19 [2] |
Details [5] | |
A | |
Mass | 1.30 M☉ |
Radius | 1.59±0.06 R☉ |
Luminosity | 4.429±0.035 [6] L☉ |
Surface gravity (log g) | 4.15±0.10 cgs |
Temperature | 6,611±80 K |
Metallicity [Fe/H] | −0.27±0.07 dex |
Rotational velocity (v sin i) | 20.2±0.7 km/s |
Age | 916 [7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
ξ Oph, Latinized as Xi Ophiuchi, is a visual binary star [9] system in the equatorial constellation of Ophiuchus. [2] It has a yellow-white hue and is faintly visible to the naked eye with a combined apparent visual magnitude of 4.39. [2] The system is located approximately 57.1 light-years (17.5 parsecs) away from the Sun based on parallax, but is drifting closer with a radial velocity of -9 km/s. [1]
The magnitude 4.40 [10] primary, designated component A, is an ordinary F-type main-sequence star with a stellar classification of F2V. [3] It is 916 [7] million years old and is rotating with a projected rotational velocity of 20 km/s. The star has 1.3 times the mass of the Sun and 1.6 times the Sun's radius. [5] It is radiating 4.4 [6] times the luminosity of the Sun from its photosphere at an effective temperature of 6,611 K. [5]
The system is a source of X-ray emission. [11] The orbiting companion, component B, is a magnitude 8.9 star at an angular separation of 35 ″ along a position angle of 27° from the primary, as of 2015. A magnitude 10.8 visual companion, component C, lies at a separation of 10.8″, as of 2004. [10]
According to Richard H. Allen's Star Names: Their Lore and Meaning (1899), ξ Oph together with θ Oph formed the Sogdian Wajrik "the Magician", the Khorasmian Markhashik "the Serpent-bitten" and with η Oph the Coptic Tshiō, "the Snake", and Aggia, "the Magician". [12]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ophiuchus |
Right ascension | 17h 21m 00.37452s [1] |
Declination | −21° 06′ 46.5710″ [1] |
Apparent magnitude (V) | 4.39 [2] |
Characteristics | |
Spectral type | F2V [3] |
U−B color index | -0.06 [4] |
B−V color index | +0.41 [4] |
Astrometry | |
Radial velocity (Rv) | −8.73±0.12 [1] km/s |
Proper motion (μ) |
RA: +265.543
mas/
yr
[1] Dec.: -202.584 mas/ yr [1] |
Parallax (π) | 57.0820 ± 0.1851 mas [1] |
Distance | 57.1 ± 0.2
ly (17.52 ± 0.06 pc) |
Absolute magnitude (MV) | 3.19 [2] |
Details [5] | |
A | |
Mass | 1.30 M☉ |
Radius | 1.59±0.06 R☉ |
Luminosity | 4.429±0.035 [6] L☉ |
Surface gravity (log g) | 4.15±0.10 cgs |
Temperature | 6,611±80 K |
Metallicity [Fe/H] | −0.27±0.07 dex |
Rotational velocity (v sin i) | 20.2±0.7 km/s |
Age | 916 [7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
ξ Oph, Latinized as Xi Ophiuchi, is a visual binary star [9] system in the equatorial constellation of Ophiuchus. [2] It has a yellow-white hue and is faintly visible to the naked eye with a combined apparent visual magnitude of 4.39. [2] The system is located approximately 57.1 light-years (17.5 parsecs) away from the Sun based on parallax, but is drifting closer with a radial velocity of -9 km/s. [1]
The magnitude 4.40 [10] primary, designated component A, is an ordinary F-type main-sequence star with a stellar classification of F2V. [3] It is 916 [7] million years old and is rotating with a projected rotational velocity of 20 km/s. The star has 1.3 times the mass of the Sun and 1.6 times the Sun's radius. [5] It is radiating 4.4 [6] times the luminosity of the Sun from its photosphere at an effective temperature of 6,611 K. [5]
The system is a source of X-ray emission. [11] The orbiting companion, component B, is a magnitude 8.9 star at an angular separation of 35 ″ along a position angle of 27° from the primary, as of 2015. A magnitude 10.8 visual companion, component C, lies at a separation of 10.8″, as of 2004. [10]
According to Richard H. Allen's Star Names: Their Lore and Meaning (1899), ξ Oph together with θ Oph formed the Sogdian Wajrik "the Magician", the Khorasmian Markhashik "the Serpent-bitten" and with η Oph the Coptic Tshiō, "the Snake", and Aggia, "the Magician". [12]