Nu Geminorum

ν Geminorum

ν Geminorum in optical light
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Gemini
Right ascension 06h 28m 57.78613s[1]
Declination +20° 12′ 43.6856″[1]
Apparent magnitude (V) 4.16[2]
Characteristics
Spectral type B6 III + B8 III[3]
U−B color index −0.47[2]
B−V color index −0.13[2]
Astrometry
Radial velocity (Rv)+39.4[4] km/s
Proper motion (μ) RA: −6.82[1] mas/yr
Dec.: −13.10[1] mas/yr
Parallax (π)5.99 ± 0.28 mas[1]
Distance540 ± 30 ly
(167 ± 8 pc)
Absolute magnitude (MV)−2.2 + −1.2[3]
Orbit[5]
Primaryν Gem Aa
Companionν Gem Ab
Period (P)53.7722 ± 0.0008 d
Semi-major axis (a)2.82 ± 0.02 mas
Eccentricity (e)0.056 ± 0.003
Inclination (i)0.98 ± 0.03°
Longitude of the node (Ω)78.9 ± 0.2°
Periastron epoch (T)MJD 51011.8 ± 0.1
Argument of periastron (ω)
(secondary)		6.7 ± 2.0°
Semi-amplitude (K1)
(primary)		51.6 ± 0.6 km/s
Semi-amplitude (K2)
(secondary)		52.5 ± 1.1 km/s
Orbit[5]
Primaryν Gem A
Companionν Gem B
Period (P)6977.3 ± 6.1
Semi-major axis (a)82.8 ± 1.3 mas
Eccentricity (e)0.241 ± 0.002
Inclination (i)75.9 ± 0.2°
Longitude of the node (Ω)121.0 ± 0.1°
Periastron epoch (T)MJD 48810.3 ± 13.0
Argument of periastron (ω)
(secondary)		226.9 ± 0.4°
Semi-amplitude (K1)
(primary)		8.0 ± 0.1 km/s
Semi-amplitude (K2)
(secondary)		15.9 ± 0.1 km/s
Details
ν Gem Aa
Mass3.34[5] M☉
Luminosity1,380[6] L☉
Temperature14,100[6] K
Rotational velocity (v sin i)160[7] km/s
ν Gem Ab
Mass3.28[5] M☉
ν Gem B
Mass3.33[5] M☉
Other designations
ν Gem, 18 Geminorum, BD+20° 1441, FK5 1173, HD 45542, HIP 30883, HR 2343, SAO 78423, WDS 06290+2013[8]
Database references
SIMBADdata

Nu Geminorum, Latinized from ν Geminorum, is a triple[5] star system in the constellation Gemini. It has an apparent visual magnitude of 4.16,[2] which is bright enough to be visible to the naked eye on a dark night. Based upon an annual parallax shift of 5.99 mas,[1] it is located at a distance of roughly 540 light years from the Sun. The position of this system near the ecliptic means it is subject to lunar occultations.[9]

The inner components of this multiple star system have an orbital period of about 54 days and a nearly circular orbit with an eccentricity of 0.056.[5] There is some uncertainty in the spectral type, with classifications ranging from a main sequence star to a giant. Orbiting the inner pair is a classical Be star, with an orbital period of 19.1 years and an eccentricity of 0.24.[5] The two orbits are co-directional and roughly coplanar. The system is overall dynamically stable, and shows no signs of Kozai-Lidov cycles. The outer Be star appears to be single.[5]

According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, this star was titled as Nucatai.[10]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Crawford1971 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cvetkovic2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  5. ^ a b c d e f g h i Cite error: The named reference Klement was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Blow_et_al_1982 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Rhoads1971 was invoked but never defined (see the help page).