Beta Scuti, Latinized from β Scuti, is a binary star system in the southern constellation Scutum. Based upon an annual parallax shift of 3.56 mas as seen from Earth,[1] it is located approximately 920 light years from the Sun. The primary component has an apparent visual magnitude of +4.22 and is radiating about 1,270 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 4,622 K.[2] This yellow-hued star is a G-type bright giant with a stellar classification of G4 IIa.[3]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Scutum |
Right ascension | 18h 47m 10.47250s[1] |
Declination | −4° 44′ 52.3271″[1] |
Apparent magnitude (V) | 4.22[2] |
Characteristics | |
Spectral type | G4IIa[3] |
U−B color index | +0.84[4] |
B−V color index | +1.09[4] |
Astrometry | |
Radial velocity (Rv) | −21.30[5] km/s |
Proper motion (μ) | RA: −8.44[1] mas/yr Dec.: −16.37[1] mas/yr |
Parallax (π) | 3.56 ± 0.43 mas[1] |
Distance | approx. 900 ly (approx. 280 pc) |
Absolute magnitude (MV) | −2.99[6] |
Orbit[7] | |
Primary | Beta Scuti A |
Companion | Bet Scuti B |
Period (P) | 834 days |
Semi-major axis (a) | 2.8 mas |
Eccentricity (e) | 0.350 |
Inclination (i) | 105.9° |
Longitude of the node (Ω) | 288.1° |
Periastron epoch (T) | 2422480.9 |
Argument of periastron (ω) (secondary) | 33.9° |
Details | |
Luminosity | 1,270[2] L☉ |
Surface gravity (log g) | 0.94[8] cgs |
Temperature | 4,622[2] K |
Metallicity [Fe/H] | -0.16[6] dex |
Rotational velocity (v sin i) | 7.8[9] km/s |
Other designations | |
Database references | |
SIMBAD | data |
This is a spectroscopic binary with an orbital period of 2.3 years and eccentricity around 0.35.[10] The secondary is about 3.3 magnitudes dimmer than the primary and estimated as type B9 based on the flux of far-ultraviolet radiation.[11]
The secondary was directly detected with a magnitude difference of 3.6 at a separation of about 17 milli-arcseconds using observations from the Navy Precision Optical Interferometer.[12] This detection was significant as observations with the Hubble Space Telescope which indicated a companion star was present were not definitive.[13] With an orbit and a parallax the sum of the masses of the two stars can be determined via a dynamical parallax.[14] This eventually can yield a precise mass for the evolved giant primary star.
Beta Scuti was a latter designation of 6 Aquilae.[15]
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