2 Equulei

2 Equulei is a double star system in the constellation of Equuleus.

2 Equulei

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Equuleus
Right ascension	21h 02m 12.50262s[1]
Declination	+07° 10′ 47.1545″[1]
Apparent magnitude (V)	6.698[2] (7.41 + 7.64)[3]
Characteristics
Spectral type	F6V[4]
Astrometry
Radial velocity (Rv)	−4.8±1.6[5] km/s
Absolute magnitude (MV)	2.16±0.18[2]
A
Proper motion (μ)	RA: −9.184[6] mas/yr Dec.: −12.915[6] mas/yr
Parallax (π)	8.8125±0.2481 mas[6]
Distance	370 ± 10 ly (113 ± 3 pc)
B
Proper motion (μ)	RA: −4.238[7] mas/yr Dec.: −17.934[7] mas/yr
Parallax (π)	8.5577 ± 0.0298 mas[7]
Distance	381 ± 1 ly (116.9 ± 0.4 pc)
Details
2 Equ A
Mass	1.73[5] M☉
Radius	3.37[8] R☉
Luminosity	13.087[8] L☉
Surface gravity (log g)	4.05[5] cgs
Temperature	6,561±80[5] K
Metallicity [Fe/H]	0.17[5] dex
Age	1.6[5] Gyr
2 Equ B
Radius	2.74[9] R☉
Luminosity	10.828 L☉
Temperature	6,330[9] K
Other designations
λ Equ, 2 Equulei, BD+06°4731, HD 200256, HIP 103813, LTT 16227, SAO 126482[10]
Database references
SIMBAD	data

The primary component of the 2 Equulei pair is an F-type main sequence star. As of 2015, the secondary had an angular separation of 2.90 arc seconds along a position angle of 213° from the primary.^[3] They form a common proper motion pair, two stars at approximately the same distance and moving in the same direction.^[4] Gaia EDR3 gives them parallaxes of 8.8125±0.2471 mas and 8.5577±0.0298 mas respectively, although they are flagged as potentially unreliable.^[6][7] These parallaxes correspond to a distance of around 380 ly, in contrast to the Hipparcos distance of 260±20 ly for the two stars as a pair.^[1]

2 Equulei has been referred to in some sources as λ (Lambda) Equulei, although it was not given that designation by Bayer.