Zeta Scuti

ζ Scuti
	Location of ζ Scuti (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Scutum
Right ascension	18h 23m 39.58309s
Declination	−8° 56′ 03.7885″
Apparent magnitude (V)	4.66
Characteristics
Spectral type	G9 IIIb Fe-0.5
U−B color index	+0.72
B−V color index	+0.94
Astrometry
Radial velocity (Rv)	−5.02 km/s
Proper motion (μ)	RA: +49.59 mas/yr ; Dec.: +51.24 mas/yr
Parallax (π)	15.78 ± 1.02 mas
Distance	210 ± 10 ly ; (63 ± 4 pc)
Absolute magnitude (MV)	0.66
Orbit
Primary	ζ Scuti A
Companion	ζ Scuti B
Period (P)	2373.7 days
Semi-major axis (a)	21.6 mas
Eccentricity (e)	0.1
Inclination (i)	89°
Longitude of the node (Ω)	226°
Periastron epoch (T)	2418278.3
Argument of periastron (ω); (secondary)	242.1°
Details
Mass	1.29 M☉
Radius	9.3 R☉
Luminosity	62.04 L☉
Surface gravity (log g)	2.61 cgs
Temperature	4,750 K
Metallicity [Fe/H]	−0.08 dex
Rotational velocity (v sin i)	1.5 km/s
Other designations
	ζ Sct, BD−09° 4712, GC 25101, HD 169156, HIP 90135, HR 6884, SAO 142267, GSC 05690-01263
Database references
SIMBAD	data

Zeta Scuti, Latinized from ζ Scuti, is the Bayer designation for a star in the southern constellation of Scutum. It is a faint star but visible to the naked eye with an apparent magnitude of 4.66.^[2] The distance to this star, as determined via parallax measurement, is around 210 light years. It is moving closer to the Sun with a radial velocity of −5 km/s.^[5]

This is an astrometric binary system with a period of 6.5 years (2,374 days) and an orbital eccentricity of 0.10.^[3] The visible component is an aging giant star of type G with a stellar classification of G9 IIIb Fe−0.5.^[3] The suffix notation indicates the spectrum displays a mild underabundance of iron. It has 1.29 times the mass of the Sun and has expanded to 9.3 times the Sun's radius.^[7] The star is radiating 62^[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,750 K.^[8]

References

^ ^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 ^e ^f 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. S2CID 119257644. Vizier catalog entry
^ ^a ^b ^c Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
^ ^a ^b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
^ ^a ^b Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
^ Jancart, S. (2005). "Astrometric orbits of S_B⁹ stars". Astronomy and Astrophysics. 442 (1): 365–380. arXiv:astro-ph/0507695. Bibcode:2005A&A...442..365J. doi:10.1051/0004-6361:20053003. S2CID 15123997.
^ ^a ^b ^c ^d Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. Vizier catalog entry
^ ^a ^b Gontcharov, G. A. (2009). "Red giant clump in the Tycho-2 catalogue". Astronomy Letters. 34 (11): 785–796. arXiv:1607.00619. Bibcode:2008AstL...34..785G. doi:10.1134/S1063773708110078. S2CID 73524157. Vizier catalog entry
^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. S2CID 54046583. Vizier catalog entry