2 Equulei

Double star system in the constellation Equuleus From Wikipedia, the free encyclopedia

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

Apparentmagnitude(V)7.41[2]
Apparentmagnitude(V)7.64[2]
Evolutionarystagesubgiant[1]
SpectraltypeF6V[4]
Quick facts Apparent magnitude (V), Characteristics ...
2 Equulei
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Equuleus
A
Right ascension 21h 02m 12.50262s[1]
Declination +07° 10′ 47.1545″[1]
Apparent magnitude (V) 7.41[2]
B
Right ascension 21h 02m 12.39375s[3]
Declination +07° 10′ 44.7957″[3]
Apparent magnitude (V) 7.64[2]
Characteristics
A
Evolutionary stage subgiant[1]
Spectral type F6V[4]
B
Evolutionary stage subgiant[3]
Spectral type F3V[5]
Astrometry
Radial velocity (Rv)−4.8±1.6[6] km/s
Absolute magnitude (MV)2.16±0.18[7]
A
Proper motion (μ) RA: −9.184[1] mas/yr
Dec.: −12.915[1] mas/yr
Parallax (π)8.8125±0.2481 mas[1]
Distance370 ± 10 ly
(113 ± 3 pc)
B
Proper motion (μ) RA: −4.238[3] mas/yr
Dec.: −17.934[3] mas/yr
Parallax (π)8.5577±0.0298 mas[3]
Distance381 ± 1 ly
(116.9 ± 0.4 pc)
Details
2 Equ A
Mass1.73[6] M☉
Radius2.6[1] R☉
Luminosity12.9[1] L☉
Surface gravity (log g)3.84[1] cgs
Temperature6,127[1] K
Metallicity [Fe/H]0.17[6] dex
Age1.9[1] Gyr
2 Equ B
Mass1.61[3] M☉
Radius2.8[3] R☉
Luminosity10.9[3] L☉
Surface gravity (log g)3.72[3] cgs
Temperature6,420[3] K
Age2.2[3] Gyr
Other designations
λ Equ, 2 Equulei, BD+06°4731, HD 200256, HIP 103813, LTT 16227, SAO 126482[8]
Database references
SIMBADdata
Close

The primary component of the 2 Equulei pair is an F-type star. As of 2015, the secondary had an angular separation of 2.90 arc seconds along a position angle of 213° from the primary.[2] They form a common proper motion pair, two stars at approximately the same distance and moving in the same direction.[4] Gaia DR3 gives them parallaxes of 8.8125±0.2471 mas and 8.5577±0.0298 mas respectively, although they are flagged as potentially unreliable.[1][3] 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.[9]

2 Equulei has been referred to in some sources as λ (Lambda) Equulei, although it was not given that designation by Bayer.[10]

References

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