6 Equulei

6 Equulei
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Equuleus
Right ascension 21h 10m 31.31410s
Declination 10° 02 56.1112
Apparent magnitude (V) 6.07
Characteristics
Evolutionary stage main sequence
Spectral type A2 Vs (A1 Si Sr Cr)
U−B color index +0.04
B−V color index +0.02
Astrometry
Radial velocity (Rv)+6.9 km/s
Proper motion (μ) RA: –0.982 mas/yr
Dec.: +17.687 mas/yr
Parallax (π)7.36±0.81 mas
Distanceapprox. 440 ly
(approx. 140 pc)
Absolute magnitude (MV)+0.236
Details
Mass2.412+0.045
−0.047
 M
Radius2.68±0.08 R
Luminosity48.7+1.9
−2.0
 L
Surface gravity (log g)3.738+0.006
−0.019
 cgs
Temperature9,339+32
−118
 K
Rotational velocity (v sin i)65 km/s
Age462+75
−71
 Myr
Other designations
BD+09°4735, HD 201616, HIP 104538, HR 8098, SAO 126597
Database references
SIMBADdata

6 Equulei is a probable (95% chance) astrometric binary star system in the northern constellation of Equuleus, located 440 light years away. It is barely visible to the naked eye as a dim, white-hued star with an apparent visual magnitude of 6.07. The system is moving further away from the Earth with a heliocentric radial velocity of +6.9 km/s. It forms a wide optical double with γ Equulei, at an angular separation of 336 arcseconds in 2011.

The visible component is an Ap star with a stellar classification of A2Vs, matching the evolutionary state of an A-type main sequence star while displaying "sharp" absorption lines. It is an estimated 460 million years old with a projected rotational velocity of 65 km/s. The star has 2.4 times the mass of the Sun and around 2.7 times the Sun's radius. It is radiating 49 times the luminosity of the Sun from its photosphere at an effective temperature of 9,339 K.