Mu Eridani, a blue subgiant star in Eridanus
Mu Eridani is a blue subgiant star in the constellation Eridanus. At 521 light years away, it shines at an apparent visual magnitude of 4.01.
Mu Eridani (HIP 22109)
Mu Eridani is a blue subgiant star in the constellation Eridanus. At 521 light years away, it shines at an apparent visual magnitude of 4.01. It is moving through the Galaxy at a speed of 28.5 km/s relative to the Sun. Its projected Galactic orbit carries it between 21,800 and 24,600 light years from the center of the Galaxy. It came closest to the Sun 4.5 million years ago when it had brightened to magnitude 2.80 from a distance of 299 light years.
Sky position: RA 4h 45.5m, Dec -3° 15'
Common designations: Mu Eridani, 57 Eridani, HIP 22109, HD 30211
Brightest stars in Eridanus:
(list all)
| Rank | Mag. | Star |
| 7 | 3.56 | Phi Eridani |
| 8 | 3.69 | chi Eridani |
| 9 | 3.70 | Tau-4 Eridani |
| 10 | 3.72 | Epsilon Eridani |
| 11 | 3.81 | Theemim |
| 12 | 3.86 | Sceptrum |
| 13 | 3.89 | Azha |
| 14 | 3.93 | Nu Eridani |
| 15 | 3.97 | 43 Eridani |
16
| 4.01
) Mu Eridani
| Rank | Mag. | Star |
| 17 | 4.04 | Beid |
| 18 | 4.08 | Tau-3 Eridani |
| 19 | 4.11 | Iota Eridani |
| 20 | 4.17 | g Eridani |
| 21 | 4.22 | Tau-6 Eridani |
| 22 | 4.24 | Kappa Eridani |
| 23 | 4.25 | Lambda Eridani |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Mu Eridani
(compared to the Sun)
E
ccentricity: 5.9% vs. 16.0%Angle φ : -176.4°vs. 26.0°
Semi-major axis : 7,115 pc vs. 8,686 pc
Semi-minor axis: 7,103 pc vs. 8,574 pc
Focus-to-center
: 417 pcvs. 1,388 pcSemilatus rectum : 7,091 pc vs. 8,464 pc
Perigalacticon: 6,699 pc vs. 7,297 pc
Apogalacticon
: 7,532 pcvs. 10,074 pcSome Tabulated XHIP Data for Mu Eridani
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 71.37558779° ±0.16 mas | 15.94 ±0.28 mas/yr. |
| Declination: | -3.25462486° ±0.11 mas | -14.52 ±0.16 mas/yr. |
| Galactic Longitude: | 200.52968251° | 20.48 mas/yr. |
| Galactic Latitude: | -29.33678238° | 6.73 mas/yr. |
Parallax: 6.25 ± 0.19 mas
Spectrography
Spectral Type: B4IV 2009A&A...501..297Z.
Radial Velocity:
23.30 ±4.10 km/s [D rating]
2006AstL...32..759G.
This star is a spectroscopic binary with an unsolved orbit.
Iron Abundance [Fe/H]:
n/a
Photometry
band
magnitude
Abs. Mag.
U
3.26
-2.76
B
3.86
-2.16
V
4.01
-2.01
R
I
4.12
-1.90
J
4.67
-1.35
H
4.57
-1.45
K
4.40
-1.62
B-V: -0.15 V-I: -0.11
Derivations
Heliocentric distance: 159.82 pc (3.0% margin of error)
Galactocentric distance: 7,531 pc
Transverse velocity: 16.3 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -130.5 pc | -48.9 pc | -78.3 pc |
| Velocity (U, V, W) | -15.9 km/s | -22.5 km/s | -7.0 km/s |