Zeta Scuti
Star in the constellation Scutum
From Wikipedia, the free encyclopedia
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]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Scutum |
| Right ascension | 18h 23m 39.58309s[1] |
| Declination | −08° 56′ 03.7885″[1] |
| Apparent magnitude (V) | 4.66[2] |
| Characteristics | |
| Spectral type | G9 IIIb Fe-0.5[3] |
| U−B color index | +0.72[4] |
| B−V color index | +0.94[4] |
| Astrometry | |
| Radial velocity (Rv) | −5.02[5] km/s |
| Proper motion (μ) | RA: +49.59[1] mas/yr Dec.: +51.24[1] mas/yr |
| Parallax (π) | 15.78±1.02 mas[1] |
| Distance | 210 ± 10 ly (63 ± 4 pc) |
| Absolute magnitude (MV) | 0.66[2] |
| Orbit[6] | |
| Primary | ζ Scuti A |
| Name | 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[7] M☉ |
| Radius | 9.3[7] R☉ |
| Luminosity | 62.04[2] L☉ |
| Surface gravity (log g) | 2.61[7] cgs |
| Temperature | 4,750[8] K |
| Metallicity [Fe/H] | −0.08[2] dex |
| Rotational velocity (v sin i) | 1.5[9] 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 |
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]