Zeta Andromedae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 47m 20.3254s[1] |
| Declination | +24° 16′ 01.841″[1] |
| Apparent magnitude (V) | 3.92 to 4.14[2] |
| Characteristics | |
| Spectral type | K1IIe[1] |
| U−B color index | +0.90[3] |
| B−V color index | +1.12[3] |
| R−I color index | +0.59[3] |
| Variable type | ELL/RS[2] |
| Astrometry | |
| Radial velocity (Rv) | −23.7 ± 0.9[1] km/s |
| Proper motion (μ) | RA: −101.23[1] mas/yr Dec.: −81.89[1] mas/yr |
| Parallax (π) | 17.98 ± 0.83[1] mas |
| Distance | 181 ± 8 ly (56 ± 3 pc) |
| Absolute magnitude (MV) | 0.3[4] |
| Details | |
| Radius | 16.0[5] R☉ |
| Temperature | 4,600[5] K |
| Rotation | 17.77 days[5] |
| Rotational velocity (v sin i) | 40[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Coordinates:
00h 47m 20.3254s, +24° 16′ 01.841″
Zeta Andromedae (Zeta And, ζ Andromedae, ζ And) is a star system in the constellation Andromeda. It is approximately 181 light years from Earth.[1]
Zeta Andromedae is an eclipsing spectroscopic binary whose primary is classified as an orange K-type bright giant with a mean apparent magnitude of +4.08. In addition to brightness variation due to eclipses, the system is also an RS Canum Venaticorum type or Beta Lyrae type variable star. Its brightness varies from magnitude +3.92 to +4.14 with a period of 17.77 days. The orbital period of the binary is 17.77 days.
Location
This star's location in the constellation Andromeda can be seen in the following diagram:

Components
A number of visual companions to the eclipsing binary have been observed. B has common proper motion with A, but C and D are probably only line-of-sight companions that have no physical association.[3]
| Multiple/double star designation: WDS 00473+2416[6] | ||||||||
|---|---|---|---|---|---|---|---|---|
| Component | Primary | Right ascension (α) Equinox J2000.0 | Declination (δ) Equinox J2000.0 | Epoch of observed separation | Angular distance from primary | Position angle (relative to primary) | Apparent magnitude (V) | Database reference |
| B | A | 00h 47m 20.2s | +24° 16′ 33″[7] | 1959 | 32.6″ | 0° | 15.3 | Simbad |
| C | A | 00h 47m 15.2s | +24° 15′ 03″[8] | 1997 | 97.0″ | 231° | 13.6 | Simbad |
| D | A | 00h 47m 08.9990s | +24° 15′ 33.584″[9] | 2006 | 155.5″ | 260° | 10.80 | Simbad |
Naming
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, ζ Andromedae itself is known as 奎宿二 (Kuí Sù èr, English: the Second Star of Legs.)[10]
References
- 1 2 3 4 5 6 7 8 9 V* zet And -- Eclipsing binary of beta Lyr type, database entry, SIMBAD. Accessed on line August 29, 2008.
- 1 2 zet And, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line August 29, 2008.
- 1 2 3 4 5 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.
- ↑ From apparent magnitude and parallax.
- 1 2 3 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
- 1 2 Entry 00473+2416, The Washington Double Star Catalog, United States Naval Observatory. Accessed on line August 29, 2008.
- ↑ BD+23 106B -- Star in double system, database entry, SIMBAD. Accessed on line August 29, 2008.
- ↑ BD+23 106C -- Star in double system, database entry, SIMBAD. Accessed on line August 29, 2008.
- ↑ BD+23 106D -- Star in double system, database entry, SIMBAD. Accessed on line August 29, 2008.
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日
External links
- Zeta Andromedae at Alcyone Software's Star Data Pages
- Image ζ Andromedae
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||