Zeta Scuti

ζ Scuti
Location of ζ Scuti (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scutum
Right ascension 18h 23m 39.58309s
Declination −08° 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
Distance210 ± 10 ly
(63 ± 4 pc)
Absolute magnitude (MV)0.66
Orbit
Primaryζ Scuti A
Companionζ 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
Mass1.29 M
Radius9.3 R
Luminosity62.04 L
Surface gravity (log g)2.61 cgs
Temperature4,750 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
SIMBADdata

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. 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.

This is an astrometric binary system with a period of 6.5 years (2,374 days) and an orbital eccentricity of 0.10. The visible component is an aging giant star of type G with a stellar classification of G9 IIIb Fe−0.5. 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. The star is radiating 62 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,750 K.