Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Andromeda |
Right ascension | 00h 47m 20.32547s[1] |
Declination | +24° 16′ 01.8408″[1] |
Apparent magnitude (V) | 3.92 to 4.14[2] |
Characteristics | |
Spectral type | K1III + KV[3] |
U−B color index | +0.90[4] |
B−V color index | +1.12[4] |
R−I color index | +0.59[4] |
Variable type | ELL/RS[2] |
Astrometry | |
Radial velocity (Rv) | −24.43 ± 0.1[5] km/s |
Proper motion (μ) | RA: −101.17[1] mas/yr Dec.: −81.77[1] mas/yr |
Parallax (π) | 17.24 ± 0.26 mas[1] |
Distance | 189 ± 3 ly (58.0 ± 0.9 pc) |
Absolute magnitude (MV) | +0.14[3] |
Orbit[3] | |
Period (P) | 17.769426 |
Semi-major axis (a) | 2.7 R* |
Eccentricity (e) | 0.0 |
Inclination (i) | 65 ± 5° |
Details | |
Aa | |
Mass | 2.6 ± 0.4[3] M☉ |
Radius | 15.9 ± 0.8[6] R☉ |
Luminosity | 95.5[3] L☉ |
Surface gravity (log g) | 2.8[3] cgs |
Temperature | 4,665 ± 140[6] K |
Metallicity [Fe/H] | −0.30[3] dex |
Rotation | 17.77 days[7] |
Rotational velocity (v sin i) | 41.4 ± 0.2[3] km/s |
Ab | |
Mass | 0.75[3] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Zeta Andromedae (Zeta And, ζ Andromedae, ζ And) is a star system in the constellation Andromeda. It is approximately 189 light-years from Earth.
Zeta Andromedae is the star's Bayer designation. It also has the Flamsteed designation 34 Andromedae and multiple other designations in stellar catalogues.
Location
[edit]![](https://upload.wikimedia.org/wikipedia/commons/thumb/0/08/Sidney_Hall_-_Urania%27s_Mirror_-_Gloria_Frederici%2C_Andromeda%2C_and_Triangula.png/170px-Sidney_Hall_-_Urania%27s_Mirror_-_Gloria_Frederici%2C_Andromeda%2C_and_Triangula.png)
The star's location is in the northern constellation Andromeda, in which it is the second-most southerly of the stars in this often drawn characteristic shape representing the mythical princess asterism, after η Andromedae.
System
[edit]![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/ZetaAndLightCurve.png/220px-ZetaAndLightCurve.png)
The system is a spectroscopic binary whose primary is classified as an orange K-type giant with a mean apparent magnitude of +4.08. Due to brightness changes caused by the ellipsoidal shape of that object, the system is also an RS Canum Venaticorum-type variable star. Its brightness varies from magnitude +3.92 to +4.14 with a period of 17.77 days, and its spectrum shows strong and variable Ca II H and K lines.[3] The orbital period of the binary is 17.77 days.
Direct imaging
[edit]The primary component of this binary system, Zeta Andromedae Aa, is one of the few stars who has been imaged directly using Doppler imaging and long-baseline infrared interferometry. With direct imaging we can recover additional information about this star.
Parameter | Value |
---|---|
Oblateness | 1.060 ± 0.011 |
Polar radius | 15.0 ± 0.8 R☉ |
Axis Inclination[a] | 70.0 ± 2.8 ° |
Pole angle[b] | 126 ± 1.9 ° |
Direct imaging also allowed observation of starspots (the analogue to sunspots), on this star, and their asymmetric distribution showed that the magnetic field of the star is generated by a mechanism different from the solar dynamo.[9] A Sun-like differential rotation of the star was observed instead.[3]
Visual companions
[edit]The WDS notes three visual companions to the eclipsing binary (Aa and Ab, forming binary A).[4] The parallax of the D star has been measured by Gaia proving its distance to be much greater than Zeta Andromedae, probably a distant red giant.[10] The closest companion, B, is likewise a background object.[11] The companion C at 97″ shares a common proper motion and a similar parallax.[12]
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Naming
[edit]In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism consisting of ζ Andromedae, η Andromedae, 65 Piscium, ε Andromedae, δ Andromedae, π Andromedae, ν Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ1 Piscium. Consequently, the Chinese name for ζ Andromedae itself is 奎宿二 (Kuí Sù èr, English: the Second Star of Legs).[14]
Notes
[edit]References
[edit]- ^ a b c d e 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. S2CID 18759600.
- ^ a b zet And, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars Archived 2017-06-20 at the Wayback Machine, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line August 29, 2008.
- ^ a b c d e f g h i j k Kővári, Zs.; Bartus, J.; Strassmeier, K. G.; Oláh, K.; Weber, M.; Rice, J. B.; Washuettl, A. (2007). "Doppler imaging of stellar surface structure. XXIII. The ellipsoidal K giant binary ζ Andromedae". Astronomy and Astrophysics. 463 (3): 1071. Bibcode:2007A&A...463.1071K. doi:10.1051/0004-6361:20065982.
- ^ a b c d HR 215, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line August 29, 2008.
- ^ Karataș, Yüksel; Bilir, Selçuk; Eker, Zeki; Demircan, Osman; Liebert, James; Hawley, Suzanne L.; Fraser, Oliver J.; Covey, Kevin R.; Lowrance, Patrick; Kirkpatrick, J. Davy; Burgasser, Adam J. (2004). "Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution". Monthly Notices of the Royal Astronomical Society. 349 (3): 1069–1092. arXiv:astro-ph/0404219. Bibcode:2004MNRAS.349.1069K. doi:10.1111/j.1365-2966.2004.07588.x. S2CID 15290475.
{{cite journal}}
: CS1 maint: unflagged free DOI (link) - ^ a b Korhonen, H.; Wittkowski, M.; Kovári, Zs.; Granzer, Th.; Hackman, T.; Strassmeier, K. G. (2010). "Ellipsoidal primary of the RS CVn binary ζ Andromedae . Investigation using high-resolution spectroscopy and optical interferometry". Astronomy and Astrophysics. 515: A14. arXiv:1002.4201. Bibcode:2010A&A...515A..14K. doi:10.1051/0004-6361/200913736. S2CID 118683792.
- ^ Strassmeier, Klaus G. (September 2009), "Starspots", The Astronomy and Astrophysics Review, 17 (3): 251–308, Bibcode:2009A&ARv..17..251S, doi:10.1007/s00159-009-0020-6
- ^ Kővári, Zsolt; Oláh, Katalin; Bartus, János; Strassmeier, Klaus G.; Granzer, Thomas (August 2006). "Spot Modelling of ζ Andromedae". Astrophysics and Space Science. 304 (1–4): 55–57. doi:10.1007/s10509-006-9073-4. S2CID 119574869. Retrieved 9 August 2022.
- ^ a b Roettenbacher, R.M.; Monnier, J.D.; Korhonen, H.; Aarnio, A.N.; Baron, F.; Che, X.; Harmon, R.O.; Kővári, Zs.; Kraus, S.; Schaefer, G.H.; Torres, G.; Zhao, M.; Ten Brummelaar, T.A.; Sturmann, J.; Sturmann, L. (2016). "No Sun-like dynamo on the active star ζ Andromedae from starspot asymmetry". Nature. 533 (7602): 217–220. arXiv:1709.10107. Bibcode:2016Natur.533..217R. doi:10.1038/nature17444. PMID 27144357. S2CID 4466687.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Entry 00473+2416, The Washington Double Star Catalog Archived April 12, 2008, at the Wayback Machine, United States Naval Observatory. Accessed on line August 29, 2008.
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日
External links
[edit]- Zeta Andromedae Archived 2011-07-07 at the Wayback Machine at Alcyone Software's Star Data Pages
- Image ζ Andromedae
- Rachael Roettenbacher, "How the face of a distant star reveals our place in the cosmos," Aeon Magazine [retrieved July 27, 2016]