Mu Crucis
  | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| 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 | |
| Evolutionary stage | subgiant[3] |
| Spectral type | B2IV-V[4] |
| U−B color index | −0.75[2] |
| B−V color index | −0.17[2] |
| μ2 Cru | |
| Spectral type | B5Vne[5] |
| U−B color index | −0.50[2] |
| B−V color index | −0.11[2] |
| Astrometry | |
| μ1 Cru | |
| Radial velocity (Rv) | +13.9[6] km/s |
| Proper motion (μ) | RA: −30.45[1] mas/yr Dec.: −13.55[1] mas/yr |
| Parallax (π) | 9.6267±0.3611 mas[7] |
| Distance | 370+23 −20 ly (113+7 −6 pc)[3] |
| Absolute magnitude (MV) | −1.49[8] |
| μ2 Cru | |
| Radial velocity (Rv) | +13[6] km/s |
| Proper motion (μ) | RA: −32.35[1] mas/yr Dec.: −10.93[1] mas/yr |
| Parallax (π) | 8.9486±0.2264 mas[9] |
| Distance | 364 ± 9 ly (112 ± 3 pc) |
| Absolute magnitude (MV) | −0.40[8] |
| Details | |
| μ1 Cru | |
| Mass | 7.0±0.1[3] M☉ |
| Radius | 3.3±0.2[3] R☉ |
| Luminosity | 1,740+170 −150[3] L☉ |
| Surface gravity (log g) | 4.25±0.05[3] cgs |
| Temperature | 20,500±250[3] K |
| Metallicity [Fe/H] | −0.21[8] dex |
| Rotational velocity (v sin i) | 31.3±0.2[3] km/s |
| Age | 9.5+5.6 −5.3[3] Myr |
| μ2 Cru | |
| Mass | 5.0[10] M☉ |
| Radius | 3.9[11] R☉ |
| Luminosity | 205[8] 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[10] Myr |
| Other designations | |
| μ Cru, WD 12546-5711, CCDM 12546-5711[13][14] | |
| 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]
References
[edit]- 1 2 3 4 5 6 7 8 Perryman, M. A. C.; et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy & Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P.
- 1 2 3 4 5 6 Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
- 1 2 3 4 5 6 7 8 9 Aschenbrenner, P.; Przybilla, N. (2026-04-03). "Quantitative spectroscopy of single and multiple OB-type stars. Non-LTE spectrum analysis with machine learning". Astronomy and Astrophysics. arXiv:2604.03082.
- ↑ Hiltner, W. A.; Garrison, R. F.; Schild, R. E. (1969). "MK Spectral Types for Bright Southern OB Stars". The Astrophysical Journal. 157: 313. Bibcode:1969ApJ...157..313H. doi:10.1086/150069.
- ↑ Levenhagen, R. S.; Leister, N. V. (2006). "Spectroscopic analysis of southern B and be stars". Monthly Notices of the Royal Astronomical Society. 371 (1): 252–262. arXiv:astro-ph/0606149. Bibcode:2006MNRAS.371..252L. doi:10.1111/j.1365-2966.2006.10655.x. S2CID 16492030.
- 1 2 Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.
- ↑ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- 1 2 3 4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ↑ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- 1 2 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 KPC from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
- 1 2 3 Zorec, J.; Arias, M. L.; Cidale, L.; Ringuelet, A. E. (2007). "Be star disc characteristics near the central object". Astronomy & Astrophysics. 470 (1): 239–247. Bibcode:2007A&A...470..239Z. doi:10.1051/0004-6361:20066615. hdl:11336/38181.
- 1 2 Chauville, J.; Zorec, J.; Ballereau, D.; Morrell, N.; Cidale, L.; Garcia, A. (2001). "High and intermediate-resolution spectroscopy of be stars 4481 lines" (PDF). Astronomy and Astrophysics. 378: 861. Bibcode:2001A&A...378..861C. doi:10.1051/0004-6361:20011202.
- ↑ "HR 4898". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-06-08.
- ↑ "HIP 63005". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-06-08.
