Mu Orionis (HIP 28614)

Mu Orionis is a white main-sequence star in the constellation Orion. It lies about 155 light years away. It is moving through the Galaxy at a speed of 9.1 km/s relative to the Sun.

Sky position: RA 6h 2.4m, Dec +9° 38.8'

Common designations: Mu Orionis, 61 Orionis, HR 2124, HD 40932, HIP 28614, Gaia DR3 3329650894896257024

Mu Orionis has the spectral type A1Vm+F2V. A-type stars are white stars with surface temperatures of roughly 7,500 to 10,000 K. Their spectra are dominated by strong hydrogen lines, and many of them rotate rapidly. Its luminosity class V means it is a main-sequence (dwarf) star, still fusing hydrogen into helium in its core like the Sun.

How to find Mu Orionis in the sky

Mu Orionis lies in Orion. With a declination of +9° 38.8', it is visible from the entire Northern Hemisphere and from the Southern Hemisphere down to about latitude 80° S. It is highest in the sky at local midnight around January, which makes the weeks around that month the best time to observe it.

Tabulated data for Mu Orionis

Astrometry and spectroscopy

Right Ascension (J2000)	90.59581950° (6h 2.4m)
Declination (J2000)	9.64727279° (+9° 38.8')
Galactic Longitude	198.68362181°
Galactic Latitude	-6.31270557°
Proper motion RA	10.43 mas/yr
Proper motion Dec	-39.09 mas/yr
Parallax	21.05 ± 0.68 mas
Spectral Type	A1Vm+F2V
Radial Velocity	0.00 km/s

Photometry

Band	Magnitude	Abs. Mag.
U	4.40	1.02
R	3.94	0.56
I	3.86	0.48
J	3.73	0.35
H	3.60	0.21
K	3.64	0.25

Derivations

Heliocentric distance: 47.51 pc (155 light years) (3.2% margin of error)
Transverse velocity: 9.1 km/s
Space velocity relative to the Sun: 9.1 km/s
Galactic position (X, Y, Z): -44.7 pc, -15.1 pc, -5.2 pc
Galactic velocity (U, V, W): 3.1 km/s, -8.3 km/s, -2.2 km/s

Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.