Observation data Epoch J2000 Equinox | |
---|---|
Constellation | Crux |
μ1 Crucis | |
Right ascension | 12h 54m 35.6249s [1] |
Declination | −57° 10′ 40.527″ [1] |
Apparent magnitude (V) | 4.03 [2] |
μ2 Crucis | |
Right ascension | 12h 54m 36.8865s [1] |
Declination | −57° 10′ 07.214″ [1] |
Apparent magnitude (V) | 5.19 [2] |
Characteristics | |
μ1 Cru | |
Spectral type | B2IV-V [3] |
U−B color index | −0.75 [2] |
B−V color index | −0.17 [2] |
μ2 Cru | |
Spectral type | B5Vne [4] |
U−B color index | −0.50 [2] |
B−V color index | −0.11 [2] |
Astrometry | |
μ1 Cru | |
Radial velocity (Rv) | +13.9 [5] km/s |
Proper motion (μ) |
RA: −30.45
[1]
mas/
yr Dec.: −13.55 [1] mas/ yr |
Parallax (π) | 9.6267 ± 0.3611 mas [6] |
Distance | 340 ± 10
ly (104 ± 4 pc) |
Absolute magnitude (MV) | −1.49 [7] |
μ2 Cru | |
Radial velocity (Rv) | +13 [5] km/s |
Proper motion (μ) |
RA: −32.35
[1]
mas/
yr Dec.: −10.93 [1] mas/ yr |
Parallax (π) | 8.9486 ± 0.2264 mas [8] |
Distance | 364 ± 9
ly (112 ± 3 pc) |
Absolute magnitude (MV) | −0.40 [7] |
Details | |
μ1 Cru | |
Mass | 7.7 [9] M☉ |
Luminosity | 1,123 [7] L☉ |
Surface gravity (log g) | 3.93 [10] cgs |
Temperature | 21,100 [10] K |
Metallicity [Fe/H] | −0.21 [7] dex |
Age | 9.2 [9] Myr |
μ2 Cru | |
Mass | 5.0 [9] M☉ |
Radius | 3.9 [11] R☉ |
Luminosity | 205 [7] L☉ |
Surface gravity (log g) | 3.40 [12] cgs |
Temperature | 20,400 [11] K |
Rotational velocity (v sin i) | 210 [12] km/s |
Age | 15.9 [9] Myr |
Other designations | |
μ1 Cru: HR 4898, CD-56°4688, HD 112092, SAO 240366, HIP 63003 | |
μ2 Cru: HR 4899, CD-56°4689, HD 112091, SAO 240367, HIP 63005 | |
Database references | |
SIMBAD | μ Cru |
μ1 Cru | |
μ2 Cru |
Mu Crucis, Latinized from μ Crucis, is the seventh-brightest star in the constellation Crux commonly known as the Southern Cross. μ Crucis is a wide double star of spectral class B stars, magnitude 4.0 and 5.2 respectively. They lie about 370 light-years away, and both stars are likely physically attached. The brighter component is known as μ1 Crucis or μ Crucis A, while the fainter is μ2 Crucis or μ Crucis B.
μ1 Crucis is the brighter of the two stars with an apparent magnitude of 4.0. It is a hot massive main sequence or subgiant star, over a thousand times as luminous as the sun.
μ2 Crucis is the fainter of the pair. Its apparent magnitude is 5.2 and it is a Be star, a star spinning so quickly that it has ejected a disc of material that creates emission lines in its spectrum. The disc is inclined at 36° to our line of sight. [11]
Observation data Epoch J2000 Equinox | |
---|---|
Constellation | Crux |
μ1 Crucis | |
Right ascension | 12h 54m 35.6249s [1] |
Declination | −57° 10′ 40.527″ [1] |
Apparent magnitude (V) | 4.03 [2] |
μ2 Crucis | |
Right ascension | 12h 54m 36.8865s [1] |
Declination | −57° 10′ 07.214″ [1] |
Apparent magnitude (V) | 5.19 [2] |
Characteristics | |
μ1 Cru | |
Spectral type | B2IV-V [3] |
U−B color index | −0.75 [2] |
B−V color index | −0.17 [2] |
μ2 Cru | |
Spectral type | B5Vne [4] |
U−B color index | −0.50 [2] |
B−V color index | −0.11 [2] |
Astrometry | |
μ1 Cru | |
Radial velocity (Rv) | +13.9 [5] km/s |
Proper motion (μ) |
RA: −30.45
[1]
mas/
yr Dec.: −13.55 [1] mas/ yr |
Parallax (π) | 9.6267 ± 0.3611 mas [6] |
Distance | 340 ± 10
ly (104 ± 4 pc) |
Absolute magnitude (MV) | −1.49 [7] |
μ2 Cru | |
Radial velocity (Rv) | +13 [5] km/s |
Proper motion (μ) |
RA: −32.35
[1]
mas/
yr Dec.: −10.93 [1] mas/ yr |
Parallax (π) | 8.9486 ± 0.2264 mas [8] |
Distance | 364 ± 9
ly (112 ± 3 pc) |
Absolute magnitude (MV) | −0.40 [7] |
Details | |
μ1 Cru | |
Mass | 7.7 [9] M☉ |
Luminosity | 1,123 [7] L☉ |
Surface gravity (log g) | 3.93 [10] cgs |
Temperature | 21,100 [10] K |
Metallicity [Fe/H] | −0.21 [7] dex |
Age | 9.2 [9] Myr |
μ2 Cru | |
Mass | 5.0 [9] M☉ |
Radius | 3.9 [11] R☉ |
Luminosity | 205 [7] L☉ |
Surface gravity (log g) | 3.40 [12] cgs |
Temperature | 20,400 [11] K |
Rotational velocity (v sin i) | 210 [12] km/s |
Age | 15.9 [9] Myr |
Other designations | |
μ1 Cru: HR 4898, CD-56°4688, HD 112092, SAO 240366, HIP 63003 | |
μ2 Cru: HR 4899, CD-56°4689, HD 112091, SAO 240367, HIP 63005 | |
Database references | |
SIMBAD | μ Cru |
μ1 Cru | |
μ2 Cru |
Mu Crucis, Latinized from μ Crucis, is the seventh-brightest star in the constellation Crux commonly known as the Southern Cross. μ Crucis is a wide double star of spectral class B stars, magnitude 4.0 and 5.2 respectively. They lie about 370 light-years away, and both stars are likely physically attached. The brighter component is known as μ1 Crucis or μ Crucis A, while the fainter is μ2 Crucis or μ Crucis B.
μ1 Crucis is the brighter of the two stars with an apparent magnitude of 4.0. It is a hot massive main sequence or subgiant star, over a thousand times as luminous as the sun.
μ2 Crucis is the fainter of the pair. Its apparent magnitude is 5.2 and it is a Be star, a star spinning so quickly that it has ejected a disc of material that creates emission lines in its spectrum. The disc is inclined at 36° to our line of sight. [11]