Mu Ophiuchi

μ Ophiuchi, Latinized as Mu Ophiuchi, is a solitary,^[10] blue-white hued star in the equatorial constellation of Ophiuchus. It is visible to the naked as a faint point of light with an apparent visual magnitude of 4.62.^[2] This object is located approximately 760 light years away from the Sun based on parallax,^[5] but is drifting closer with a radial velocity of −18.5 km/s.^[4]

Mu Ophiuchi

Location of μ Ophiuchi (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Ophiuchus
Right ascension	17h 37m 50.71308s[1]
Declination	−8° 07′ 07.5749″[1]
Apparent magnitude (V)	4.62[2]
Characteristics
Spectral type	B8II-IIIp:Mn[3]
U−B color index	−0.20[2]
B−V color index	+0.11[2]
Astrometry
Radial velocity (Rv)	−18.50[4] km/s
Proper motion (μ)	RA: −11.31[5] mas/yr Dec.: −20.47[5] mas/yr
Parallax (π)	4.32 ± 0.20 mas[5]
Distance	750 ± 30 ly (230 ± 10 pc)
Absolute magnitude (MV)	-2.24[6]
Details
Radius	11.1+2.1 −0.6[1] R☉
Luminosity	398.7±26.8[1] L☉
Temperature	7,748+210 −651[1] K
Metallicity [Fe/H]	+0.00[7] dex
Rotational velocity (v sin i)	95[8] km/s
Other designations
μ Oph, 57 Ophiuchi, BD−08°4472, FK5 3399, GC 23889, HD 159975, HIP 86284, HR 6567, SAO 141772[9]
Database references
SIMBAD	data

This object has a stellar classification of B8II-IIIp:Mn,^[3] showing a luminosity class with mixed traits of a giant or bright giant star. The suffix notation indicates it is a candidate chemically peculiar star with an overabundance of manganese in its spectrum. It may be a mercury-manganese star.^[11] This object has 11 times the radius of the Sun and is radiating nearly 400 times the Sun's luminosity from its photosphere at an effective temperature of 7,748 K.^[1] It is spinning with a projected rotational velocity of 95 km/s.^[8]

In 2006, a new nearby star cluster, Mamajek 2 (/ˈmæmədʒɛk/), was discovered. Mu Ophiuchi is a candidate member.^[12] The cluster has an estimated age of 120±25 million years.^[13]

References

1. 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.
2. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
3. Cowley, A. (November 1972). "Spectral classification of the bright B8 stars". Astronomical Journal. 77: 750–755. Bibcode:1972AJ.....77..750C. doi:10.1086/111348.
4. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
5. Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
6. 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. Vizier catalog entry
7. Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. S2CID 118345778. Vizier catalog entry
8. Abt, Helmut A.; et al. (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573 (1): 359–365. Bibcode:2002ApJ...573..359A. doi:10.1086/340590.
9. "mu. Oph". SIMBAD. Centre de données astronomiques de Strasbourg.
10. Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
11. Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
12. Mamajek, Eric E. (2006). "A New Nearby Candidate Star Cluster in Ophiuchus at d = 170 pc". Astronomical Journal. 132 (5): 2198–2205. arXiv:astro-ph/0609064. Bibcode:2006AJ....132.2198M. doi:10.1086/508205. S2CID 14070978.
13. Jilinski, E.; et al. (January 2009). "Dynamical Evolution and Spectral Characteristics of the Stellar Group Mamajek 2". The Astrophysical Journal. 691 (1): 212–218. arXiv:0810.1198. Bibcode:2009ApJ...691..212J. doi:10.1088/0004-637X/691/1/212. S2CID 15570695.