Mu Orionis

μ Orionis
Location of μ Ori (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
μ Ori A
Right ascension 06h 02m 22.997s
Declination +09° 38′ 50.24″
Apparent magnitude (V) 4.30
μ Ori B
Right ascension 06h 02m 23.009s
Declination +09° 38′ 50.52″
Apparent magnitude (V) 6.27
Characteristics
μ Ori A
Spectral type A1 Vm
U−B color index +0.11
B−V color index +0.14
μ Ori B
Spectral type F2 V
U−B color index +0.00
B−V color index +0.43
Astrometry
Radial velocity (Rv)0.00 km/s
Proper motion (μ) RA: 10.43 mas/yr
Dec.: −39.09 mas/yr
Parallax (π)21.69±0.13 mas
Distance150.4 ± 0.9 ly
(46.1 ± 0.3 pc)
Absolute magnitude (MV)Aa: 0.93
Ba: 3.53
Bb: 3.53
Orbit
Primaryμ Ori A
Nameμ Ori B
Period (P)6,813.8±1.2 d
Semi-major axis (a)0.2737±0.0021"
(12.620±0.057 AU)
Eccentricity (e)0.7410±0.0011
Inclination (i)96.028±0.028°
Orbit
Primaryμ Ori Aa
Nameμ Ori Ab
Period (P)4.4475849 days
Semi-major axis (a)0.001661±0.000013"
(0.07659±0.00058 AU)
Eccentricity (e)0.0037±0.0014
Inclination (i)47.1±9.0°
Semi-amplitude (K1)
(primary)
1.03±0.26 km/s
Semi-amplitude (K2)
(secondary)
> 4.58 km/s
Orbit
Primaryμ Ori Ba
Nameμ Ori Bb
Period (P)4.7835349 days
Semi-major axis (a)0.001688±0.000013"
(0.07659±0.00036 AU)
Eccentricity (e)0.0016±0.0014
Inclination (i)110.71±0.73°
Semi-amplitude (K1)
(primary)
1.72±0.26 km/s
Semi-amplitude (K2)
(secondary)
2.02±0.26 km/s
Details
μ Ori Aa
Mass2.38 M
Radius2.85 R
Luminosity32.2 L
Temperature8,300 K
Rotational velocity (v sin i)10 km/s
Age282 Myr
μ Ori Ab
Mass0.652 M
μ Ori Ba
Mass1.389 M
Radius1.33 R
Luminosity3.0 L
Temperature6,600 K
μ Ori Bb
Mass1.356 M
Radius1.33 R
Luminosity3.0 L
Temperature6,600 K
Other designations
Mu Orionis, Mu Ori, μ Orionis, μ Ori, 61 Orionis, 61 Ori, HR 2124, HD 40932, HIP 28614, BD+09°1064, ADS 4617, WDS J06024+0939, 2MASS J05351889-0516140
Database references
SIMBADdata
data2
data3

μ Orionis (Latinised to Mu Orionis, abbreviated to μ Ori or Mu Ori) is a quadruple star system in the constellation Orion, similar to Mizar and Epsilon Lyrae with combined visual magnitude of 4.13. The four stars are known as Mu Orionis Aa, Mu Orionis Ab, Mu Orionis Ba, and Mu Orionis Bb. The A and B systems are several tenths of an arcsecond apart. The entire system is located approximately 150 light years from the Sun.