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Beta Scuti

Star in the constellation Scutum

β Scuti

Location of β Scuti (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Scutum
Right ascension	18h47m 10.474s[1]
Declination	−04° 44′ 52.342″[1]
Apparent magnitude (V)	4.22[2]
Characteristics
Evolutionary stage	Giant star
Spectral type	G4IIa[3]
U−B color index	+0.84[4]
B−V color index	+1.09[4]
Astrometry
Radial velocity (Rv)	−28.75±4.88[1] km/s
Proper motion (μ)	RA: −7.972 mas/yr[1] Dec.: −16.398 mas/yr[1]
Parallax (π)	4.8549 ± 0.3403 mas[1]
Distance	670 ± 50 ly (210 ± 10 pc)[1]
Absolute magnitude (MV)	−2.99[5]
Orbit[6]
Primary	Beta Scuti A
Companion	Beta 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
Radius	49.26+3.24 −3.72[7] R☉
Luminosity	1,315±186[7] L☉
Surface gravity (log g)	0.94[8] cgs
Temperature	4,951±25[7] K
Metallicity [Fe/H]	-0.16[5] dex
Rotational velocity (v sin i)	7.8[9] km/s
Other designations
β Sct, BD-04°4582, FK5 1489, GC 25730, GSC 05122-01426, HIP 92175, HR 7063, HD 173764, SAO 142618, CCDM 18472-0445
Database references
SIMBAD	data

Beta Scuti, Latinized from β Scuti, is a binary star system in the southern constellation Scutum. Based upon an annual parallax shift of 4.85 mas as seen from Earth,^[1] it is located approximately 670 light years from the Sun.

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 primary component has an apparent visual magnitude of +4.22 and is radiating about 1,315 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 4,951 K.^[7] This yellow-hued star is a G-type bright giant with a stellar classification of G4 IIa.^[3] Its angular diameter was measured at 2.121 milliarcseconds by the Navy Precision Optical Interferometer, which gives it a physical radius of approximately 49 R_☉ at the estimated distance.^[7]

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]