Zeta Boötis

Zeta Boötis, Latinized as ζ Boötis, is a binary star system in the constellation of Boötes that consists of two giant stars with matching stellar classifications of A2III.[5] They have the Flamsteed designation 30 Boötis. This system is approximately 180 light years[1] from Earth and has a combined apparent magnitude of +3.78.[2] The individual magnitudes differ slightly, with component A having a magnitude of 4.43[3] and component B at the slightly dimmer magnitude 4.83.[4]

ζ Boötis

Location of ζ Boötis (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Boötes
Right ascension	14^h 41^m 08.95158^s[1]
Declination	+13° 43′ 41.8967″[1]
Apparent magnitude (V)	3.78[2] (4.43[3]/4.83[4])
Characteristics
Spectral type	A2III / A2III[5]
U−B color index	+0.05[2]
B−V color index	+0.05[2]
Astrometry
Radial velocity (Rv)	-5.5[6] km/s
Proper motion (μ)	RA: +51.95[1] mas/yr Dec.: -11.08[1] mas/yr
Parallax (π)	18.07 ± 1.24[1] mas
Distance	180 ± 10 ly (55 ± 4 pc)
Absolute magnitude (MV)	+0.13[7]
Orbit[8]
Companion	CCDM 14411+1344 B
Period (P)	45,460 ± 62 days
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)	JD 2460183.5 ± 57
Argument of periastron (ω) (secondary)	262.9 ± 5.9°
Details
Luminosity	81[7] L☉
Other designations
ζ Boo, 30 Boötis, BD+14° 2770, GC 19777, HD 129247/129246, HR 5478/5477, SAO 101145, ADS 9343, CCDM 14411+1344[3][4][9]
Database references
SIMBAD	data

The binary nature of this system has been tracked since 1796. They complete an orbit roughly every 45,460 days, or 124.46 years. The next close approach will occur during August 2023. The orbit of this pair has a very high eccentricity of 0.9977, bringing the stars within 0.3 AU at their closest approach.[8]

• 
  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

1. 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
2. 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
3. "HR 5478 -- Star in double system", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-18
4. "HR 5477 -- Star in double system", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-18
5. Edwards, T. W. (April 1976), "MK classification for visual binary components", Astronomical Journal, 81: 245–249, Bibcode:1976AJ.....81..245E, doi:10.1086/111879
6. Evans, D. S., "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 held at the University of Toronto 20-24 June, 1966, Academic Press, London, p. 57, Bibcode:1967IAUS...30...57E
7. 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.
8. Muterspaugh, Matthew W.; et al. (December 2010), "The Phases Differential Astrometry Data Archive. II. Updated Binary Star Orbits and a Long Period Eclipsing Binary", The Astronomical Journal, 140 (6): 1623–1630, arXiv:1010.4043, Bibcode:2010AJ....140.1623M, doi:10.1088/0004-6256/140/6/1623
9. "CCDM J14411+1344AB -- Double or multiple star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-18

External links

• Kaler, James B., "ZETA BOO (Zeta Bootis)", Stars, University of Illinois, retrieved 2011-12-18
• HR 5477
• Image Zeta Boötis
• CCDM J14411+1344