Beta Equulei

Beta Equulei, Latinized from β Equulei, is the Bayer designation for a solitary^[9] star in the northern constellation of Equuleus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.16.^[2] The annual parallax shift is 11.27 mas,^[1] indicating a separation of around 289 light years from the Sun. It is drifting closer with a radial velocity of −11 km/s.^[6]

Beta Equulei

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Equuleus
Right ascension	21h 22m 53.61365s[1]
Declination	+06° 48′ 40.1125″[1]
Apparent magnitude (V)	5.16[2]
Characteristics
Evolutionary stage	Main sequence[3]
Spectral type	A3 V[4]
U−B color index	+0.10[5]
B−V color index	+0.064±0.003[2]
Astrometry
Radial velocity (Rv)	−11.1±0.8[6] km/s
Proper motion (μ)	RA: +53.685[1] mas/yr Dec.: +10.136[1] mas/yr
Parallax (π)	11.2696±0.2608 mas[1]
Distance	289 ± 7 ly (89 ± 2 pc)
Absolute magnitude (MV)	+0.13[2]
Details
Mass	2.74±0.04[3] M☉
Radius	4.02[7] R☉
Luminosity	78.3[2] L☉
Temperature	9,000[7] K
Rotational velocity (v sin i)	58.0±0.7[4] km/s
Age	600[7] Myr
Other designations
β Equ, 10 Equulei, BD+06°4811, HD 203562, HIP 105570, HR 8178, SAO 126749, WDS 21229+0649A[8]
Database references
SIMBAD	data

This is an ordinary A-type main sequence star with a stellar classification of A3 V.^[4] It has 2.7 times the mass of the Sun^[3] and about four^[7] times the Sun's radius. The star is around 600^[7] million years old – 93%^[3] of the way through its main sequence lifetime – and is spinning with a projected rotational velocity of 58 km/s.^[4] It is radiating 78^[2] times the luminosity of the Sun from its photosphere at an effective temperature of about 9,000 K.^[7] The star emits an infrared excess indicating the presence of a dusty debris disk. The mean temperature of the dust is 85 K, indicating the semimajor axis of its orbit is 104 AU.^[7]

β Equulei has four optical companions. They are not physically associated with the star described above.^[10]