Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Boötes |
Right ascension | 14h 41m 08.95158s [1] |
Declination | +13° 43′ 41.8967″ [1] |
Apparent magnitude (V) | 3.78 [2](4.46 + 4.55) [3] |
Characteristics | |
Spectral type | A2III + A2III
[4] A1V [5] |
U−B color index | +0.05 [2] |
B−V color index | +0.05 [2] |
Astrometry | |
Radial velocity (Rv) | −8.5±0.6 [6] km/s |
Proper motion (μ) |
RA: +51.95
[1]
mas/
yr Dec.: -11.08 [1] mas/ yr |
Parallax (π) | 18.07 ± 1.24 mas [1] |
Distance | 180 ± 10
ly (55 ± 4 pc) |
Absolute magnitude (MV) | +0.13 [7] |
Orbit [8] | |
Companion | B |
Period (P) | 45,460±62 d |
Semi-major axis (a) | 2.3±1.7″ |
Eccentricity (e) | 0.9977±0.0034 |
Inclination (i) | 102.3±9.2° |
Longitude of the node (Ω) | 8.2±2.6° |
Periastron epoch (T) | 2,460,183.5±57 JD |
Argument of periastron (ω) (secondary) | 262.9±5.9° |
Details | |
Luminosity | 81 [7] L☉ |
Other designations | |
A: HD 129247, HR 5478 [10] | |
B: HD 129246, HR 5477 [11] | |
Database references | |
SIMBAD | data |
Zeta Boötis, Latinized from ζ Boötis, is a binary star system in the constellation of Boötes. They have the Flamsteed designation 30 Boötis; Zeta Boötis is the Bayer designation. This system is visible to the naked eye with a combined apparent magnitude of +3.78. [2] The individual magnitudes differ slightly, with component A having a magnitude of 4.46 and component B at the slightly dimmer magnitude 4.55. [3] It is located at a distance of approximately 180 light years from the Sun based on parallax, [1] but is drifting closer with a radial velocity of −9 km/s. [6]
The duplicity of this star was discovered by English astronomer William Herschel in 1796, and their changing positions have been tracked from 1823 onward. [12] They complete an orbit roughly every 124.5 years (45,460 days). The orbit of this pair has a very high eccentricity of 0.9977, bringing the stars within 0.3 AU at their closest approach. The next close approach will occur during August 2023. [8]
In 1976, T. W. Edwards found a stellar classification of A2III for both components, suggesting they may be evolved A-type giant stars. Helmut A. Abt reported a class of A2V in 1981, which matches an A-type main-sequence star. [13] Abt and Nidia Morrell updated the classification to A1V in 1995. [5] Considering the extreme nature of their orbit, it is unlikely that any companion exoplanets could have stable orbits around either star. [14]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Boötes |
Right ascension | 14h 41m 08.95158s [1] |
Declination | +13° 43′ 41.8967″ [1] |
Apparent magnitude (V) | 3.78 [2](4.46 + 4.55) [3] |
Characteristics | |
Spectral type | A2III + A2III
[4] A1V [5] |
U−B color index | +0.05 [2] |
B−V color index | +0.05 [2] |
Astrometry | |
Radial velocity (Rv) | −8.5±0.6 [6] km/s |
Proper motion (μ) |
RA: +51.95
[1]
mas/
yr Dec.: -11.08 [1] mas/ yr |
Parallax (π) | 18.07 ± 1.24 mas [1] |
Distance | 180 ± 10
ly (55 ± 4 pc) |
Absolute magnitude (MV) | +0.13 [7] |
Orbit [8] | |
Companion | B |
Period (P) | 45,460±62 d |
Semi-major axis (a) | 2.3±1.7″ |
Eccentricity (e) | 0.9977±0.0034 |
Inclination (i) | 102.3±9.2° |
Longitude of the node (Ω) | 8.2±2.6° |
Periastron epoch (T) | 2,460,183.5±57 JD |
Argument of periastron (ω) (secondary) | 262.9±5.9° |
Details | |
Luminosity | 81 [7] L☉ |
Other designations | |
A: HD 129247, HR 5478 [10] | |
B: HD 129246, HR 5477 [11] | |
Database references | |
SIMBAD | data |
Zeta Boötis, Latinized from ζ Boötis, is a binary star system in the constellation of Boötes. They have the Flamsteed designation 30 Boötis; Zeta Boötis is the Bayer designation. This system is visible to the naked eye with a combined apparent magnitude of +3.78. [2] The individual magnitudes differ slightly, with component A having a magnitude of 4.46 and component B at the slightly dimmer magnitude 4.55. [3] It is located at a distance of approximately 180 light years from the Sun based on parallax, [1] but is drifting closer with a radial velocity of −9 km/s. [6]
The duplicity of this star was discovered by English astronomer William Herschel in 1796, and their changing positions have been tracked from 1823 onward. [12] They complete an orbit roughly every 124.5 years (45,460 days). The orbit of this pair has a very high eccentricity of 0.9977, bringing the stars within 0.3 AU at their closest approach. The next close approach will occur during August 2023. [8]
In 1976, T. W. Edwards found a stellar classification of A2III for both components, suggesting they may be evolved A-type giant stars. Helmut A. Abt reported a class of A2V in 1981, which matches an A-type main-sequence star. [13] Abt and Nidia Morrell updated the classification to A1V in 1995. [5] Considering the extreme nature of their orbit, it is unlikely that any companion exoplanets could have stable orbits around either star. [14]