Zeta Boötis
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| ζ Boo | |
| Right ascension | 14h 41m 08.95158s[1] |
| Declination | +13° 43′ 41.8967″[1] |
| Apparent magnitude (V) | 3.78[2] (4.46 + 4.55)[3] |
| HIP 71759 | |
| Right ascension | 14h 40m 42.39288s[4] |
| Declination | +13° 32′ 03.5621″[4] |
| Apparent magnitude (V) | 5.925[5] |
| Characteristics | |
| ζ Boo | |
| Spectral type | A1V[6] |
| U−B color index | +0.05[2] |
| B−V color index | +0.05[2] |
| HIP 71759 | |
| Spectral type | F0V[7] |
| B−V color index | 0.227[5] |
| Variable type | δ Scuti[8] |
| Astrometry | |
| ζ Boo | |
| Radial velocity (Rv) | −8.5±0.6[9] km/s |
| Proper motion (μ) | RA: +51.95 mas/yr[1] Dec.: −11.08 mas/yr[1] |
| Parallax (π) | 18.56±0.76 mas[1] |
| Distance | 176 ± 7 ly (54 ± 2 pc) |
| Absolute magnitude (MV) | +0.13[10] |
| HIP 71759 | |
| Proper motion (μ) | RA: +54.399 mas/yr[4] Dec.: −15.481 mas/yr[4] |
| Parallax (π) | 19.3257 ± 0.0511 mas[4] |
| Distance | 168.8 ± 0.4 ly (51.7 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.37[8] |
| Orbit[11] | |
| Primary | ζ Boo A |
| Companion | ζ Boo B |
| Period (P) | 125.04+0.24 −0.21 years |
| Semi-major axis (a) | 41.84+0.46 −0.44 au |
| Eccentricity (e) | 0.98045 |
| Inclination (i) | 125.88±0.16° |
| Longitude of the node (Ω) | 176.63±0.16° |
| Periastron epoch (T) | 2023.9548 |
| Argument of periastron (ω) (secondary) | 62.08+0.13 −0.14° |
| Details[11] | |
| ζ Boo A | |
| Mass | 2.21+0.14 −0.05 M☉ |
| Radius | 2.6+0.3 −0.4 R☉ |
| Temperature | 8,800+1,000 −600 K |
| Age | 560+150 −240 Myr |
| ζ Boo B | |
| Mass | 2.15+0.10 −0.03 M☉ |
| Radius | 2.4±0.3 R☉ |
| Temperature | 8,750+800 −550 K |
| Age | 560+150 −240 Myr |
| HIP 71759 | |
| Mass | 1.79±0.29[8] M☉ |
| Radius | 1.70±0.05[8] R☉ |
| Luminosity | 9.01±0.22[8] L☉ |
| Surface gravity (log g) | 4.23±0.08[8] cgs |
| Temperature | 7,660±107[8] K |
| Other designations | |
| ζ Boo, 30 Boötis, BD+14°2770, GC 19777, HIP 71795, SAO 101145, ADS 9343, CCDM 14411+1344, WDS J14411+1344[12] | |
| A: HD 129247, HR 5478[13] | |
| B: HD 129246, HR 5477[14] | |
| HIP 71759: BD+14 2769, HD 129153, HR 5473, SAO 101137, TIC 119613557, TYC 917-1472-1 | |
| Database references | |
| SIMBAD | data |
| HIP 71759 | |
| SIMBAD | data |
Zeta Boötis is a triple star system in the constellation of Boötes. Its name is a Bayer designation that is Latinized from ζ Boötis, and abbreviated Zeta Boo or ζ Boo. They have the Flamsteed designation 30 Boötis. This system is visible to the naked eye as a point of light with an apparent visual magnitude of +3.78.[2] The individual magnitudes of the components differ slightly, with component A having a magnitude of 4.46 and component B at the slightly dimmer magnitude 4.55.[3] The system is located at a distance of approximately 180 light years based on parallax,[1] but is drifting closer to the Sun with a radial velocity of −9 km/s.[9]
Observations
[edit]The duplicity of this star was discovered by English astronomer William Herschel in 1796, and their changing positions have been tracked from 1823 onward.[15]
In 1976, T. W. Edwards found a stellar classification of A2III for both inner 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.[16] Abt and Nidia Morrell updated the classification to A1V in 1995.[6]
Characteristics
[edit]The two components of the inner pair, Zeta Boötis A and B, are A-type main-sequence stars. Component A has 2.21 times the Sun's mass, 2.6 times the Sun's radius and an effective temperature of 8,800 K. Component B has 2.15 times the Sun's mass, 2.4 times the Sun's radius and an effective temperature of 8,750 K. Their estimated age is 560 million years.[11]
The stars take 125 years to orbit each other. The orbit of this pair has a very high eccentricity of 0.98045, bringing them within 0.818 au at their closest approach (periastron). As of 2025[update], the eccentricity of this system is possibly the second-highest known, after HIP 26245, whose eccentricity is 0.985±0.002. The last periastron occurred during November 2023.[11] Considering the extreme nature of their orbit, it is unlikely that any exoplanets could have stable orbits around either star.[17]
Together with the star HIP 71759, Zeta Boötis make a triple star system. This distant star has an estimated orbital period of three million years, being at an observed distance of 41,300 au (6,180×109 km; 0.653 ly) from the inner pair. The orbit of this star is likely what forced the high eccentricity orbit of the inner pair, via the Kozai mechanism.[18] It has a class of F0V, matching an F-type main-sequence star.[7] It is a Delta Scuti variable with a brightness amplitude of 0.00134 magnitudes.[8]
Gallery
[edit]-
Zeta Bootis imaged with the Nordic Optical Telescope on 13 May 2000 using the lucky imaging method. (The Airy discs around the stars is diffraction from the 2.56m telescope aperture.) -
Typical short-exposure image of a binary star, as seen using speckle imaging through the Earth's atmosphere.
References
[edit]- ^ a b c d e van Leeuwen, F. (November 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, S2CID 18759600.
- ^ a b c d Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
- ^ a b Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27 – L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ a b Abt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
- ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
- ^ a b c d e f g h Lv, C.; Esamdin, A.; Hasanzadeh, A.; Ghazinejad, M.; Pascual-Granado, J.; Mirouh, G. M.; Karimov, R. (June 2024), "Statistical analysis of asteroseismic indices and stellar parameters of TESS-observed δ Scuti stars", Astronomy and Astrophysics, 686: A174, Bibcode:2024A&A...686A.174L, doi:10.1051/0004-6361/202346985, ISSN 0004-6361.
- ^ a b Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ 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. XHIP record for this object at VizieR.
- ^ a b c d Waisberg, Idel; Klein, Ygal; Katz, Boaz (2025-05-27), "Which is the most eccentric binary known? Insights from the 2023/4 pericenter passages of Zeta Boötis and Eta Ophiuchi", The Open Journal of Astrophysics, 8, arXiv:2504.17858, doi:10.33232/001c.138625, ISSN 2565-6120.
- ^ "zet Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-31.
- ^ "zet Boo A". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-31.
- ^ "zet Boo B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-31.
- ^ Wierzbiński, St. (1956), "Orbites des étoiles doubles", Acta Astronomica, 6: 82, Bibcode:1956AcA.....6...82W.
- ^ Abt, H. A. (1981), "Visual multiples. VII. MK classifications", The Astrophysical Journal Supplement Series, 45: 437, Bibcode:1981ApJS...45..437A, doi:10.1086/190719.
- ^ Muterspaugh, Matthew W.; et al. (December 2010), "The Phases Differential Astrometry Data Archive. III. Limits to Tertiary Companions", The Astronomical Journal, 140 (6): 1631–1645, arXiv:1010.4044, Bibcode:2010AJ....140.1631M, doi:10.1088/0004-6256/140/6/1631, S2CID 9272936.
- ^ Waisberg, Idel; et al. (March 2024), "Hidden Companions to Intermediate-mass Stars. XVI. Unveiling a 41,300 au Companion to the Very Eccentric Binary Zeta Boötis", Research Notes of the AAS, 8 (3): 55, Bibcode:2024RNAAS...8...55W, doi:10.3847/2515-5172/ad2df5, ISSN 2515-5172.
External links
[edit]- Kaler, James B., "ZETA BOO (Zeta Bootis)", Stars, University of Illinois, retrieved 2011-12-18
- HR 5477
- Image Zeta Boötis
- CCDM J14411+1344
